slackbuilds_ponce/audio/clam_annotator

The CLAM Annotator is a tool that can be used to visualize, check and
modify music information extracted from audio: low level features, note
segmentation, chords, structure... The tool is intended to be useful
for music information retrieval research.

Among other things, CLAM Annotator can analyze a song (wav/mp3/ogg file)
and display the chord changes in realtime, as the song plays.

This requires clam.