Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Chordbase Lite - Chordbase Lite is a paperless solution for the gigging musicians to display lyrics and chords on mobile devices.
MMA - “MMA—Musical MIDI Accompaniment” is an accompaniment generator.
Guitarix - Guitarix is a simple Linux Rock Guitar Amplifier for https://alternativeto.
Sundog Scale Studio - The MIDI chords and melodies laboratory
SongBook - SongBook is a music app that helps you to manage your song collections complete with lyrics and chords.