Beat tracking for MIDI and audio

[Mutzu]

I believe tracking the tempo aka beat tracking of music is a missing key feature in Live.

At the moment, it seems to be necessary to add warp markers to an audio track that is set to "lead".

But extracting the tempo and tempo changes(!) from a MIDI clip and audio clip would be very practical.

This would also be an enhancement for an audio track set to "lead".

I need this feature to preserve subtle tempo changes from the recordings from my MIDI keyboard. I think they make the music more alive. Then I could add other MIDI tracks that align with the leading track.

Therefore, setting a MIDI track as a tempo lead track would be nice. If we could add warp markers to MIDI tracks, it would be more comfortable to shape MIDI recordings than by stretching or squeezing a selection of MIDI notes. Because this requires to move the other MIDI notes before or after the squeezing/stretching.

My current problem is that MIDI clips do not follow the tempo changes of a lead audio track. They become longer when I activate "lead" for an audio track.

At least, a Follow button for MIDI clips would be great. It should make MIDI clips follow an audio lead track just as following audio tracks do. Then I could bounce the original MIDI track and use it as a tempo lead track.

Logic Pro has a feature called Beat Mapping:

https://www.youtube.com/watch?v=2iFgDAvJeOQ&t=315s

I found this technical paper from a presentation I witnessed years ago:

https://ofai.at/papers/oefai-tr-2000-09.pdf

I was impressed by the performance of this algorithm.

[Mutzu]

Melodyne offers nice ways to edit the tempo that would be cool to have in Live's clip view and arrangement view. Adapting the length of the bars makes it easier to grasp visually how this influences the playback.

https://youtu.be/ATBgOLJzJsc