Adaptive tempo and time stretch challenge

[Rytm]

Hello,

I play drums and percussion. From time to time I wish I had more arms and legs to do the stuff I want to do. There are some tracks that we are playing live in the big band (or the soul band for that matter) that would require 3 percussionists. Enter Ableton Live. I could just sample my self during rehearsal and let Live do the complementary work while performing. But how do we keep the live and machine tempo in sync?

Now that would not be a problem if we could just use click track, you say. Well, big band feel (and the older dudes in the brass section for that matter) kind of prevents that approach. So that would mean that I would need to control the tempo of the machine as we play.

I have devised a machine in my brain, see below. Now my question to you is: Is Live and Max the platform to pull the thing off and actually build something like this? Are there building blocks in the Live / Max domain to support this or should I look elsewhere? I assume the triggering bit is no problem, but how about the rest?


This is how envision the thing to work:

1. I have a sample, lets say 4 bars of percussion
2. I mark hitpoints (yes cubase lingo) on the sample so the software knows where the beats are located. Also the default tempo where no time stretch is applied is indicated in the system. The sample must use a time stretch algorithm to maintain pitch while changing tempo.
3. I have some kind of trigger devise where I can start and stop playing of the sample
4. I have another trigger devise where I mark the current beat the band is actually playing (while doing percussion, feet are rarely used anyways)
5. So now the band is playing. Before I hit the start-stop, I tap the current tempo the band is playing to set the current tempo. At a certain point in time I hit the start-stop trigger and the sample starts playing in the tempo I have tapped.
6. While performing, I keep on tapping tempo. Now, we need like some kind of PID controlling algorithm to support the adjustment of the IS and SHOULDBE tempo of the sample in a smooth and adaptable way. Parameters of sensitivity would need to be set. Also needed, a symmetric time "fence" around each beat where the solution is sensitive to tempo adjustment within the fence but not outside. I'm thinking that the tempo match trigger could then be set on the base drum of a kit drummer, which would still allow for the occational double beat or fill, while still maintaining control of tempo analysis and adjustment.) We also need a rule stating that if no beat indication is detected within the fence, the system maintains the current tempo. In this way the solution is not sensitive to if we do tempo tap once every bar or at each trigger point.

Hope you can help!

Best regards,

//Slipperman

[Ryder17]

I also dream of such a device! If ableton could just match the beats as well as tempo to your tapping, Ableton would be sooo much better for using in a live band context

[AustinThumper]

I've always been disappointed with the various tap tempo functions in daws and sequencers. Yes, they do a good job of computing bpms by averaging tap intervals, etc, but the thing I've never seen is a "chase to beat" function. Meaning, when I hit the trigger, that is the beat. Right now. That means sending the necessary midi clocks to complete the bar, for instance. Or it might mean (if all syncs for this bar have been sent) to wait for the next trigger.

How this would be done with warping is trickier. Sending midi start/stop/sync is simpler. Good luck playing a strict 4/4 kick throughout the whole song though.

There was a hardware device called a kahler human clock that sent midi sync. It purported to be smart enuf so you could play more a natural kick pattern, and it would track it. No idea how that worked..

[jasper]

I have it.
I need a week to get it to you.
WRITE DOWN MY ABLETON SCREEN NAME.

-Mike

[Ryder17]

written down. do hurry!