Audio Playback to Assist with Transcription

I would like the ability to import audio (MP3, WAV, etc.) and start synchronized playback with the MIDI/Notation reader. (I am NOT asking for MuseScore to convert the audio to MIDI or Notation.) It would be very helpful in two situations: 1) when I need to transcribe a pre-recorded work for a local band (and yes, copyrights will be respected!) and 2) when working with musicians who do not sight read but want to be accompanied by strings, keys or choral groups who need notation.

This feature would allow arrangers to copy the timing precisely and, more importantly, ensure that additions to arrangements really are the enhancements that the arranger hoped for.

A handy companion feature that I have seen in proprietary apps like Cakewalk Sonar is the ability to clap or tap along to the audio track, and then the software sets the MIDI tempo to precisely match the "metronome" track.