I would like to suggest some new devices for Live: audio-to-midi units.
The first would generate note-on and velocity midi events from an audio
channel. Pitch could be extracted from a simple filtered FFT and
wouldn't have to be extremely exact; velocity from the average amplitude
over a short sample; and data sent out at the beat rate or via something
like how beat-repeat generates sounds. Note-off might need to be
supplied via some sort of dialed-in delay for incoming sound textures,
or threshold based on volume for impulses or solo instrumental tracks.
The second would generate a midi controller event that is assignable and
based on pitch or amplitude of the incoming signal. Data would be sent
out at a rate that could be dialed in. This could be used, for example,
to extract an automation envelope from pitch or volume and assign that
midi stream to a parameter in Simpler, Impulse, or Sampler, etc. That
way we could have an envelope follower, or a harmony accompanied.
I think that simplicity and low CPU utilization should have preference
over accuracy if that is an issue in the software.
