Max for Live MIDI Effect – Prevent Re-triggering Notes While Sustain Is Held

Overview

I am looking for an experienced Max for Live (Max/MSP) developer to create a custom MIDI effect for Ableton Live that prevents repeated note-on events from stacking while a note is already sounding, including sustain pedal behavior.

The goal is to replicate the keying behavior of a tonewheel organ (e.g., UAD Waterfall), where re-pressing the same key does not retrigger or add volume until the key and sustain are fully released.

This device will be used in a live performance keyboard rig, so stability, predictability, and low CPU overhead are critical.

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Required Behavior (Core Logic)

Per MIDI note (pitch):

• Allow the first Note On event

• If the same note is played again while it is already active, block the Note On

• Sustain pedal (CC64) must be respected

• While sustain is held:

– Notes remain “active”

– Re-triggering the same note does nothing

• Only allow a note to retrigger after:

– The key has been released

– AND the sustain pedal has been released

This logic must be per-note, not global or monophonic.

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Functional Requirements

• Must be a Max for Live MIDI Effect

• Must work reliably in Ableton Live 11

• Must support polyphony (chords)

• Must correctly handle sustain pedal (CC64)

• Must prevent amplitude stacking caused by repeated note-ons

• Must introduce negligible CPU overhead

• Must not alter timing or velocity of allowed notes

• Should include a simple on/off toggle (optional but preferred)

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Deliverables

• Final .amxd Max for Live device

• Confirmation of tested behavior with sustain pedal

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Nice to Have (Optional)

• Panic/reset button to clear all active notes

• Clean, minimal UI

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Developer Requirements

• Proven experience with Max/MSP and Max for Live

• Familiarity with MIDI note handling and CC messages

• Comfortable working with state-based MIDI logic

• Ability to test with sustain pedal behavior

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Budget & Timeline

Open to proposals.

This is a small, focused utility, not a large plugin.

Please include:

• Relevant Max for Live examples you have built

• Estimated timeline

• Fixed price or hourly estimate