Meludia - Listening exercises and to sharpen your ear and music theory skills
Guitarix - Guitarix is a simple Linux Rock Guitar Amplifier for https://alternativeto.
GNU Solfege - GNU Solfege is free music education software.
AmpliTube - Guitar Amp & FX modeling plug-in • Amp, Stomp, Cabinet + Mic, Rack FX modeling
Auricula - Practice your sense of hearing and learn to identify intervals for your musical development.
Ampire - State Space Modeled guitar amp/cab/stompbox simulator.