Keezy Drummer - Make a beat in seconds
Guitarix - Guitarix is a simple Linux Rock Guitar Amplifier for https://alternativeto.
AutoDrum - AutoDrum" is free, open source software for automatic drum performance.
GNUitar - GNUitar is guitar effects software that allows you to use your PC as guitar processor.
Band-in-a-Box - Band-in-a-Box is so easy to use!
Ampire - State Space Modeled guitar amp/cab/stompbox simulator.