Recently I made a little musical sketch that used a field recording of fireworks. I wanted a drone to be triggered whenever a loud firework happened. This was easy to do using a gate device, with the side chain input being audio from the track with the fireworks on. I also wanted another element - a synth to play notes from a scale, using the same process of having the fireworks trigger the notes. There isn’t an inbuilt Ableton Live device which does this, so Max was the obvious choice.
There are three different types of Max for Live devices, MIDI Effects, Audio Effects. and Instruments. What I needed was a hybrid of an Audio Effect device and an Instrument device, since I wanted to analyse the audio, then send a MIDI note to a device on the same track. There isn’t a way of doing this as far as I'm aware, so I chose a combination of an Audio Effect on one track for the analysis, and a MIDI effect on a different track to receive MIDI notes.
I created a little device to look for peaks in the amplitude using Max/MSP's peakamp~ object. I then set a release time, or the minimum time between peaks/notes, and used Max's keyboard display to draw a scale. Then I made an option for playing the scale repeatedly upwards, downwards, or randomly, and finally added a note length parameter. It was all pretty rushed, but here's the basic user interface.
This music is just a little sketch, and will probably remain so, but it shows how easy it can be to do things that would have been a bit more complicated before Max for Live.