Violin by Trala - Violin by Trala is a music learning app that is designed specifically for Violin users.
Guitarix - Guitarix is a simple Linux Rock Guitar Amplifier for https://alternativeto.
Metronaut - An app to help you play classical music
Ampire - State Space Modeled guitar amp/cab/stompbox simulator.
Piano2Notes - Piano2Notes is a web application and mobile that transcribes your piano tune into a digital word document.
TH-U - World class guitar amps and effects for PC and Mac