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The Latency Generation
We’ve all seen Ray Charles in The Blues Brothers Movie ripping it up on a beat up old Fender Rhodes and marveled at Stevie Wonder’s Arp Odyssey freestyle bass lines over countless albums throughout the 1970s. There was a time when keyboards begged to be played – once your fingers hit the keys you couldn’t leave them alone. I spent countless hours in music shops as a kid messing with Minimoogs and Arps and Oberheims – they were all way out of my price range by a million miles but I wanted them all so badly because of how playing them made me feel. Keyboards were the stuff of dreams and visions. This passion for an electronic instrument is something I feel we have lost mostly in the digital age. I don’t see the same level of player enthusiasm for keyboards or synthesizers in people generally. Not like there used to be anyway. You can call it nostalgia for retro gear or vintage sounds and memories of past experiences but I feel it is something far deeper than that.
I had a friend over the other day – he is a first rate keyboard player – he gigged as a young man using EP-200s and D6 Clavinets. He sold these in the late 80’s like most people and bought midi modules and controllers and later moved into software. I have an old 1976 Roland System 101 analogue keyboard in the studio and he asked if I minded if he had a play. No problem. Four hours later I had to pull the plug so he would go home and let me go to bed. With all his midi gear and softsynths he admitted to feeling mostly uninspired as a player to really play like he used to with same passion as he remembered and yet on this night he could not leave this beat up old monosynth alone and in his playing you could feel the passion and the pleasure coming from the monitors themselves.
Music as it should be.
We discussed the experience at great length the next day and we both concluded that the sole reason behind this renewed enthusiasm and unforced creative expression came from the simple fact that the key-to-note response time is mostly instantaneous in a lot of vintage gear. Arps, Moogs, Rolands, Oberheims – when you press a key the note sounds in microseconds and when your fingers come off the key the note ends just as fast. His natural desire to keep playing had nothing to do with the sounds of the synth or retro nostalgia – he was unaware that he was playing for nearly four hours. This instant keyboard response time is like fingers on guitar strings or hands on a conga skin – feel takes over and expression just happens. He compared the mono-synth response to that of his old D6 Clavinet and anyone who has ever played a real one will know that they almost spit at you when you hit the keys, the response time is that fast. I asked him about Clavinet patches in his midi modules and software emulations. His answer was simple – they sound authentic but the slow response time changes the way you interact with the keys and consequently the expression and feel is much poorer and he finds himself less inspired to actually play.
This is most peoples experience with computer latency and softsynths where response time is never much better than 7ms even on a very good system. I watch people play everyday on these systems and I never see that same level of passion or expression. What I see is playing with no real feel with the knowledge that it will be quantized after the recording anyway. Where is the expression in that? Where is the passion for and connection to an instrument? More disturbing perhaps is that this disapointing experience is broadly accepted as the way things are and should be graciously accepted. And it’s not all about software and computers either. Plenty of modern hardware ‘virtual’ and DSP based instruments suffer from key to note latency also. They sound good but do they begged to be played? Do they keep you awake at night because you can’t leave them alone? The answer is mostly no they do not.
Most/all music taught in schools now is software/controller/PC based. Does this mean we are fostering and indeed encouraging an entire generation that will have no experience of feeling instant key to sound in their playing? What does this mean for feel and expression in playing and composition for the future?
If the significance of this experience is lost on those of us that understand how fundamentally different it feels using these vintage instruments with instant response times, what then is the logical conclusion to this trend when all that remains are new generations of electronic musicians who only know software emulations and visit museum displays to look at the heritage behind glass?
The Future is Late.
"Thursday 19th October, 2006 - I was up early this morning, and for some reason I got involved in testing the sync between the G5 and the laptop. In my world the days of tight sync are long gone (Vince and I spoke fondly of remembered sync boxes - the SRC Friend-Chip, the SBX-80, FSK from the MC4, The Unitor on the Atari) - but obviously sync inside one computer is good. A colleague on the Logic User List suggested trying sending MTC over Ethernet (supported by the OSX) which I had never done. I got extremely tight sync, but only about 1 in 10 times when I started the sequencer. "
An excerpt taken from a weblog by Gareth Jones – Engineer/Producer – Depeche Mode/Erasure
http://www.garethjones.com/news/erasureNews.html
http://www.garethjones.com/
How can a CV/Gate Sequencer be Sloppy?
The stability of any sequencer (CV/Gate/Midi/Din) is only as good as the clock driving it and how the design deals with processor/CPU interrupts as far as the tempo/clocking/step goes. Some are better than others. In the case of any sequencer that can be self driven under its own tempo clock - do the test and see how tight individual steps are relative to each other. Now clock it from a stable external Midi Clock master and do the tests again - might be better, might be worse - dependant on design philosophy. Some new sequencers do OK under self sync but lose the plot totally when you run them slaved to even the best Midi Clock input.
Why?
Poor design basically. Instead of making sure the external Clock gets a hot-line direct to the sequencer clocking circuit - a badly written OS running on a single IC that looks after the whole operation means even the tightest external sync gets stuck in bad city traffic on the way to running the sequencer properly.
Red Light, Green Light. Stop. Start. Just hold on a second while I scan some keys and switches and then I'll get back to keeping time properly......I'm sure you get the point.
The above CPU instruction flow chart is from a well known and very popular vintage (1982) CV/Gate step sequencer. A quick look at the microprocessor task routine and the time intervals between them shows very clearly why this model will always be a loose rubber band on the timing stakes which it most certainly is.
There are hundreds of different step sequencers in existence but just having CV/Gate outputs and even external analogue clocking does not guarantee any of them can keep good time.
Early step CV sequencers just followed incoming Square Clock pulses - as long as that was rock solid, so was the step sequencer.
Over the last 25 years, as discreet/CMOS voltage-based sequencer design [Clocks/Timers/Latches/Gate Arrays) gave way to monolithic CPU/ICs with shared resources for both tempo generation and step/event/serial processing - our simple, stable, uninterrupted Pulse Train Express design gradually became all stations to Sloppy Town
.
The sequencer input and output method - CV/Gate/Trigger/Midi/Din - makes no difference at all. Tempo clock source stability and internal handling is where it's at.
For a look at Sequencer Design that really does do timing justice, click on the Analogic-ACS link above or visit their website.
http://www.analogic-acs.com/home.html
Is Time Absolute?
In 1967, the 13th General Conference on Weights and Measures first defined the International System (SI) unit of time, the second, in terms of atomic time rather than the motion of the Earth. Specifically, a second was defined as the duration of 9,192,631,770 cycles of microwave light absorbed or emitted by the hyperfine transition of cesium-133 atoms in their ground state undisturbed by external fields.
Human Feel
"I've figured out how to program personality into the Synclavier. I can adjust one track to within one millisecond, and I can change the starting time of one track as opposed to another. Doing that shows me everything, it shows me how feels are created. You know, if you lay a snare drum a bit back, if you make it a bit lazy, it becomes someone, and if you make it a bit pushy, it becomes someone else. That's what makes the sound really. The sound of something has to do with the way it's played - whether it's a program or a player..."
S.J. Lipson [Engineer/Co-Producer - Frankie Goes to Hollywood, Grace Jones:Slave to the Rhythm]
May 1987 - Music Technology Magazine
Why don't people write slow sequenced music anymore?
While working in the studio a week or so ago, something I had long suspected to be true revealed itself.
I was testing the offset between a number of devices – TR-909, Elektron Machine Drum and a Dave Smith Evolver. By rights – running the Machine Drum as Midi Clock master via a reliable passive powered hardware midi-thru box (Korg KMP-68 in this instance) and driving both the TR-909 and the Evolver as Midi Clock Slaves ‘should’ provide a reasonably good synchronized playback system. The Machine Drum has a very stable Midi Clock sync stream output even when driving the unit very hard (lots or Parameter Locks/Notes/LFOs etc) so as a Midi Clock master it is an ideal choice.
From my prior experience I already knew that there would be some timing offsets despite the Machine Drum providing good clock. My test setup proved this – 16th Click track from the MD into the reference input of the Russian Dragon and 16th Rim Shot from the TR-909 into the test input of the Russian Dragon. At 120 BPM the TR-909 Rim Shot lagged at between 4 and 5 ms behind the MD reference click. Similarly – a fast zero attack 16th noise pulse from the Evolver ran about 3-4 ms behind the MD ref. click.
‘Start’ lag time, once measured is in most cases the same regardless of the song tempo and can be corrected a number of ways. I was about to move on when for some reason or another I decided to drop the tempo to 60 BPM and check the results.
Same mean offset (TR-909 5 ms lag, Evolver 4 ms lag against the MD ref. click.) but the Russian Dragon showed something far more interesting.
[For those of you unfamiliar with the venerable Russian Dragon – the unit has LEDs that show to 1ms accuracy how far apart two signals are from each other. If two signals are reliably 4 ms apart then the 4th LED from centre will light firmly. If the offset varies between 3ms and 5ms then the 3rd, 4th and 5th LEDs from centre will flash as the signals move around.]
Back to my experiment. At 120 BPM the TR-909 sat mostly 4ms behind the MD ref. click with the 5ms LED flashing every now and again. At 60 BPM – the 4ms LED was still the average but 3ms and the 4ms LEDs were also lit much more frequently. I dropped the tempo to 30 BPM just to follow the thought process and low and behold – same 4 ms LED average but now the variance was bouncing anywhere between 1ms and 9ms on the LEDs.
What is going on? Assuming the master tempo clock source is stable even at very slow tempos - which the MD SPS1 is in fact - there are two reasons for the erratic behaviour of the slave devices.
1. The slave devices ability to maintain tight tempo stability is compromised when run from an external clock source - this is most likely happening at a design/Operating System level.
2. In the case of later generation DSP sequencer/Drum/Synth sequencers - the execution of real-time DSP sound generation compromises tempo/clock/event timing precision. The DSP has to 'make' the sounds before it can 'play' the sounds. For that reason - the sequencer tempo/event scheduling is forced to push-pull in order to work around the DSP engine.
What does all this mean? If you have a live rig or a studio setup with multiple devices synchronized together then working at faster tempos narrows this step/event jitter window of perception. A good analogy for this – a movie projector running at 30 frames per second appears to our eyes as a seamless moving picture. Slow the same film down to 10 frames per second and we see the picture flicker immediately.
Speeding sequencers up gives us the sonic illusion that everything is synced up and quantized perfectly when in reality all we have done is narrowed the gaps.
Slow things down and the reality is plain to hear – welcome to Sloppy Town.
In my early days of composing electronic music on computers – it always puzzled me why, when I slowed the sequencer down to work on certain sections – the sequence itself sounded very average indeed, almost unlistenable, but at normal tempo (say 100 BPM plus) things sounded OK.
I also remember many early attempts to compose sequenced material on PCs at 75 BPM or even lower and always despairing at why it never had the snap, crackle and pop of say a James Brown live funk/soul workout.
When you stand a long way back from a painting on a gallery wall you see a portrait.
Move in close and you see the brushstrokes.
Music by Numbers
(Everything has a place in time)
At any tempo, each and every single rhythmic step and interval has a precise location or length in time. This is not a variable. It is a strict absolute. It has nothing to do with art or creativity. The click track - be it internal or machine driven, fixed or variable - is the foundation bedrock on which music is made. It is the musicians' artistic canvas. When painting or drawing, a graphic artist requires a steady surface on which to lay pen or brush. No graphic medium artist would accept a moving canvas on which to create anything meaningful. Music technology has evolved much in terms of pure sound quality in recent years - the brushes and colours of our craft - 24/96 kHz sampling, precision word clocks for digital audio, a million perfectly recorded bass and string patches to choose from and so on, but our ability to accurately sequence and replay these sounds in time has regressed almost to the point of being unusable. Our canvas is less stable now than it was twenty years ago.
What’s a millisecond or two between friends?
I think timing is a very personal thing - I've been working in studios and with sequencers and electronics for nearly 20 years and I've had the good fortune to use a lot of good (and bad) equipment over that time.
Many years ago I borrowed a TR-808 off a friend. I loved it but eventually he wanted it back of course. In my innocence I hatched a plan. I had an Apple Performer 580 running Logic with an Opcode interface and an Akai S-3200XL sampler. I spent a whole weekend sampling the TR-808 to perfection and happily returned the TR-808 to its owner. The next weekend I started writing TR-808 patterns into Logic. I was stunned and surprised to find none of my patterns gave me the same 'rush' as I had felt playing the TR-808 itself. I spent hours checking quantising, polyphony, sample start times - you name it. It did my head in.
I borrowed the TR-808 again thinking it was just my ears playing tricks - sure enough - soon as I hit play on the TR-808 - it blew me away with how straight up funky and engaging it sounded - it made me want to stay up all night and play which is the object after all!
So - I devised a crude but effective test - my partner at the time was a dancer - great feel and incredible body/rhythmic timing but she knew nothing about technology or making music. I recorded 10 or so patterns out of the TR-808 to DAT. Next I programmed identical patterns in Logic firing the S-3200XL samples via the Opcode Midi Interface and then recorded these to DAT also - same levels, same balance. Next I stuck 60 seconds of each on a CD, in pairs (the same pattern but by each method of sequencing) but mixed up which came first or second over the whole 10 pairs. - I wrote down which was which and stuck the paper in my pocket.
I gave the CD to my girlfriend and told her to play it as many times as she wanted and told her to write down which of each pair she was drawn to the most just on the basis of how it 'felt'.
Out of all 10 pairs she chose every single one made using the actual TR-808 itself. This was a revelation.
The following weekend I made some audio file measurements and even though the TR-808 was not razor precise by any means - the Mac/Logic/Opcode/S3200XL slopped around more particularly where say a Kick/Hat and Clap were on the same step. More importantly, the average extra slop between intervals on the sampled grooves and the original TR-808 recordings was no more than 3 ms!
Which ever way you look at it - with no technical or musical theory knowledge at all - a human being was naturally drawn to music and rhythm with a 3 ms tighter overall groove.
We don't have to understand it - but we can all feel it.
The TR-808 is not super-tight by any means but what saves it is that it has no polyphony/midi/step issues - you can layer a Kick/Snare/Hat/Tom/RS and Clap all on step 1 of a pattern and they will all fire bang on top of each other. In Midi Land you get a nice little arpeggio rather than a tight 'crack'.
Compression, EQ, Bit Rate...... or just fix the timing?
The more you surround yourself with beats and rhythms that nail it timing wise - the more your ears do start to pick up when things are even slightly off.
A while back I was testing the sync between a certain percussion sequencer and my Akai MPC-3000; I had the 3K Click sample in solo running for about 3 minutes in the background of my studio while I was doing some patching. I stopped it and re-started but this time listened to the percussion sequencer instead and before 2 bars had recorded I knew it wasn't up to the MPC-3000 well before I did any tests.
In the early days my sequencing used to be faster and busy - 130 BPM plus - lots of 16ths. When you speed things up it narrows all the gear/midi/software slop so you get the illusion that things are tight. Slow things up and the slop that's been there all along really opens up and you can drive a bus through the holes mostly! Keeping things busy fills up the holes too. When things are not working in a track often the first thing we all do is add something else rather than fixing what is already there. I realised a while back that if you can make a track work at slower tempos with plenty of space you are doing something right. Then it really sounds hot when you speed things up. You need ultra-tight clocks and tight sync to get this happening and most current workstations, sequencing hardware and software apps just don't cut it enough in my opinion - I wish they did!
An experienced recording engineer told me when I was a young studio assistant in the UK that if a Mix wasn't working, backtrack and mute everything then unmute one track at a time - the instant you unmute a track and it loses the groove or it changes your listening focus then you know what you need to work on. These days I apply that principle to rhythmic programming. I get the timing as tight as I can from the first sound I record and then only add something if it adds to or complements the feel. If you have a Kick/Snare doing simple 'Boom-Tick-Boom-Boom-Tick' in your track - you really should be able to listen to just those to elements for the length of your song and not get bored. I guarantee you - if you do get bored within 8 bars - it's not the Kick or the Snare sound or the compression or the EQ or the pattern or even the repetition - it’s the timing of the sequencer that's driving it.
When the timing is spot-on even a straight quarter note metronome sounds funky!
Blinded by the Light
We all have emotional and financial investment in the equipment we buy and use and with that investment we put faith in the tools and really wish and hope and want to believe that they are worth their weight and cost. However - sometimes we can be blinded by our investment. A close friend who spent a hefty sum of money on a Mac/Logic rig a few years back spent the best part of a year refusing to acknowledge what he could plainly hear - that his external Midi stuff sounded sloppy as all hell. He did everything - groove templates, micro event adjustments, moved his room around, changed his mix position - he even stopped listening to tight production by other people because it reminded him of how rough his own material sounded! His emotional and financial investment kept him from hearing the truth - his new rig just didn't do Midi justice - period. After a few beers one afternoon I convinced him to let me bring over my Atari/Notator/Unitor system and hook it up to his Midi gear. Next we copied some of his midi files to Notator Format. I'll never forget the look on his face when he pressed the space bar. Priceless - the illusion falls away and you can go back to what you know is right even if you have to buck the trend and use a computer that is 20 years old to get there. But from there you can move forward. It's about listening without prejudice and saying 'yes - that 20 year old sequencer makes the hairs stand up on the back of my neck' and 'no - this new one that I have just spent a months salary on doesn't cut it'. Only then can you begin to ask 'why?' and once you start to find out why you can begin to do something about it.
A Tale of Two Sequencers
One of the reasons I got stuck into testing timing in sequencers recently was that I had always felt one of my newer percussion sequencers moved around the rest of my other kit a little more than it should have. Only one or maybe two kick drums playing within a two bar pattern had the same even tone each step whereas the others all sounded like they had slight pitch modulation. Closer inspection revealed that they were moving around enough time-wise to sound odd and, aside from messing with the overall bottom-end in the track; it blurred the edges of an otherwise tight and punchy groove. Recording the pattern directly into an audio editor software application showed clearly the kicks were playing push-pull instead of staying locked in position as they should. The machine in question definitely had some Internal Step-Event/Tempo-Clock Precision issues.
Why is this important?
When we improve sequencer timing precision the better the music sounds. It doesn't matter if it's 140 BPM hard-techno or 65 BPM hard-swung swamp funk. In fact, the slower the tempo the more you need real tempo clock and event stability to keep the funk/groove going. Any chump with a rubber band groove box can fudge it at 140 BPM. Likewise it is easy to sequence at anything above 125 BPM and think it sounds acceptable. This is because the sloppy bits and offsets are much closer together at higher tempos and they are not nearly as noticeable. You can run a whole studio full of very sloppy gear together in sync at 130 BPM and get away with it sort of. By contrast, at 65 BPM, the holes and the rough edges are so big you have nowhere to hide. A loose event-clock makes a very lumpy sounding track at that tempo no matter what tricky stuff you do with accents and groove templates.
Take the Pepsi Challenge!
1. Line up ten percussion sequencers/samplers/drum machines of your choice – hardware or software.
2. Sequence up identical sounding hard-quantised break-beat patterns on all of them and set the tempos all at 135 BPM.
3. Now listen to each in turn and pick a favourite just going by feel.
4. After the last one go back to the first but drop all the tempos by 10 BPM.
5. Again listen to all ten and pick your favourite.
6. Keep going remembering to drop the tempos by 10 BPM each time.
They might be even until you get to 90 BPM or lower but when the holes and rough edges start to widen with the slower tempo then the units with the poor internal clock/event stability start to show their true colours.
When you really get down there in the sub-60 BPM range only a rare handful truly give up the funk without changing a thing.
I Dream of Jeannie
A new Sequencer Specification Standard.
Instead of note storage capacity, polyphony, sample rate, connectors, USB etc - all the usual stuff - the primary task of any sequencer is to play events in time so here is our sequencer specification wish list for the future.
1. Internal Tempo/Clock Precision [+/- 0.000 BPM measured over 10 minutes]
2. Max. Internal Voice Generation to Internal Step Trigger error [+/- 0.00ms/x number of samples at 44.1 kHz]
3. Polyphony Timing Precision - Step/Tick Event Internal voice alignment under maximum load - all voices on a single event tick.
4. Outgoing Midi Clock Precision.
5. Incoming Midi Clock Sync to Internal Sequencer Clock/Grid offset in samples/ms.
Smoke and Mirrors
You shouldn’t be surprised really, computers are sequential machines – it’s all a plate spinning act. With analogue circuitry all the hardware is there all the time.
G.H. 17th May 2001
Time Travel – Exploring the Fourth Dimension
There is much fantasy literature and film exploring Time Travel and The Fourth Dimension.
Time travel as a concept has been a long standing fascination for humanity for many reasons and yet through music we find a very real way of entering this fourth dimension every day.
If you take the accepted method of defining any point in 3 dimensional space by latitude, longitude and altitude and apply this instead to sound or music in stereo you arrive at Pan Position (Left to Right), Mix Depth (Front to Rear) and Centre Frequency (Top to Bottom). It is fairly simple then to grasp the understanding that a mix engineer’ job is to place, shape and blend multiple sounds into a three dimensional sound space. Less obvious is that mixing also directly involves manipulating with these sounds in the fourth dimension – time.
Music is a real-time experience and most music involves repetition and rhythm. This fundamental aspect means we can interact with and alter our perspective in this fourth dimension as a very important part of the creative process just like we can with the other three. A simple example of this might be say the use of a delay line to add echo to or even change the timing placement of a snare in a mix to change the rhythmic feel.
Much effort, energy and financial outlay is spent understanding and improving our audio production techniques and equipment relative to the first three dimensions. Think of the hundreds of thousands of magazine articles written over the years discussing Microphone Capsule design, Compressor and EQ transparency, Mix Bus definition, Tube versus Solid state, 3rd Order Harmonic Distortion, Analogue Filter characteristics, Monitor Mid Range presence, Soft Dome or Ribbon Tweeter design, Word Clock precision to improve DAW audio jitter – I could fill a book and still not touch on the sheer volume of what we all do to improve our tools for playing with and improving sound in the three common dimensions.
As mysterious as the Fourth Dimension is in fantasy so too it seems in music production also.
Scan through any audio production or music technology magazine and look for examples of articles discussing timing or rhythmic placement or studio tools that deal with tempo and timing in interesting ways.
If music is made up of these four core dimensions and all of them hold at least equal significance in the production and listening experience of music then why is the fourth neglected?
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