Repitch
This free MIDI Max for Live device is basically just a MIDI transpose knob, similar to Ableton's "Pitch" MIDI effect. The twist is that when you change the pitch, rather than waiting till your next note is played to transpose the MIDI, this device shifts the pitch of all your held MIDI right away. Allowing for all sorts of modulation possibilities.
The “Quantize” parameters can keep the changing of the transposition in time. You can also limit the speed of the replayed transpositions with the “Speed Limit” parameter to keep things from getting too crazy during automation. Or leave both off to embrace the wildness of the device sending midi notes at as close to signal rate at it can while it transposes. You can get this effect is by mapping a signal rate device like Ableton's LFO onto it and putting it on any wave except square.
The “Lowest” and “Highest” parameters filter out notes above of the below them respectively.
This device works well with devices that can map MIDI notes to a parameter, such as my Bend Keys and Bend Map devices used together. These devices can be found individually or in the “Bend Series” pack on my website.