Question: Is there a tool that can help me edit individual notes in a polyphonic audio sample?

If you want a tool to edit individual notes in a polyphonic audio sample, Samplab is a great choice. This AI-powered polyphonic audio sample editing tool for music producers and DJs lets you manipulate and process audio samples, including editing notes and drums in polyphonic audio. It also has options like MIDI file export, tempo and key shifting, and stem separation into instrumental, drum, bass and vocal elements. Samplab is available as a VST3 and AU plugin or desktop app that integrates directly with DAWs, with Basic and Premium versions.

Another tool worth checking out is RipX DAW, an AI-powered music production tool that's particularly good at advanced stem separation and editing. You can split mixed audio into individual stems, edit notes, and replace instruments or vocals. The PRO version adds stem clean-up, audio repair modules and a variety of effects geared for producers, DJs, musicians and educators. RipX DAW is available for both macOS and Windows and offers a 21-day free trial.

If you prefer a transcription-oriented approach, Klangio offers an AI-powered music transcription platform that turns audio recordings or YouTube links into sheet music, MIDI and MusicXML files. It includes instrument-specific tools like Piano2Notes and Guitar2Tabs, and polyphonic detection is possible. Klangio is available as a web app and mobile app, so it's a good option for musicians at any level.