Suspension Pedal, Max for Live MIDI device

You’re prob­a­bly famil­iar with the piano’s sus­tain ped­al, and how that works. When you press it, it dis­ables the mechan­i­cal action that ends a note when you take your hand off a key. When you release the ped­al, that action is re-enabled. 

That’s the extreme­ly sim­pli­fied expla­na­tion that a MIDI key­board­’s sus­tain ped­al repro­duces, at any rate. While the ped­al is pressed, notes ring indef­i­nite­ly, allow­ing you extra time to repo­si­tion your hands, but also cre­at­ing a mud­dy dis­so­nant mess if you’re not careful.

There’s anoth­er vari­a­tion, called the sostenu­to ped­al, which you’re prob­a­bly less famil­iar with. Essen­tial­ly, the notes that were held down when you depress the ped­al con­tin­ue to ring indef­i­nite­ly, but notes pressed sub­se­quent to that are still end­ed by lift­ing your fin­gers off the keys. So you can, for exam­ple, strike a dra­mat­ic chord and play short notes on top of it with­out hav­ing to leave one or both hands on that held chord.

Most MIDI soft­ware and devices don’t sup­port the sostenu­to ped­al, but the mag­ic of script­ing allows us to cre­ate it, if desired.

What I’ve cre­at­ed isn’t quite that, either. It’s a third ped­al behav­ior that I don’t think I’ve seen before. I’m call­ing it a sus­pen­sion pedal.

The notes that were held when you depress the ped­al ring out indef­i­nite­ly. Then while the ped­al is pressed, all input from your key­board is ignored. Final­ly, at the moment you release the ped­al, it changes to whichev­er keys you hap­pen to be pressing. 

Mean­ing…
If you’ve released a note, that note ends.
If you’ve added a note, that note sounds.
If you’ve left a note alone, it con­tin­ues to sound.

This was specif­i­cal­ly devised for sit­u­a­tions where you’re con­trol­ling mul­ti­ple instru­ments simul­ta­ne­ous­ly. Add this device to one instru­men­t’s device chain, and you can force that instru­ment to fall in and out of sync with the oth­ers harmonically.

And here’s the down­load link:
Sus­pen­sion Ped­al v1.0

Ver­sion 2 will have a con­fig­urable thresh­old, so if you’re using a more expres­sive con­trol (which sends a full range of CCs rather than sim­ple on/off mes­sages), you can set dif­fer­ent instances to trig­ger at dif­fer­ent lev­els. Unless in test­ing, that proves to be a ter­ri­ble idea, at which point there is no ver­sion 2.

Edit:
It was­n’t a ter­ri­ble idea, but I’m not sure the added com­plex­i­ty is of tremen­dous ben­e­fit to any­one. I’ll leave both ver­sions avail­able, but for the moment, I think I pre­fer v1 myself.
Sus­pen­sion Ped­al v2.01

2.01 added a non­de­script grey but­ton below the thresh­old slid­er. Press­ing it sets the thresh­old slid­er to match what­ev­er the ped­al slid­er is cur­rent­ly set to. This should make it eas­i­er to set things “by feel”; map the ped­al slid­er first, find your sweet spot, and press the but­ton to lock that into place.

Note: All three of these con­trols can be mapped to automa­tion clips, or the out­put of oth­er apps. I can’t think of a sin­gle rea­son why you’d want to do that, but I left the option open.