Buzztrax aims to be a music studio that allows one to compose songs using
only a computer with a soundcard. If you've used tracker programs like
FastTracker, Impulse Tracker, or the original AMIGA SoundTracker, that will
give you an idea of how one can sequence music in Buzztrax. The Buzztrax
editor uses a similar concept, where a song consists of a sequence with
tracks and in each track one uses patterns with events (musical notes and
control changes).

In contrast to other Tracker programs, tracks are not simply sample players:
a user can make a song using an arrangment of virtual audio plugins that
are linked together to create different effects. Each of these machines can
be controlled realtime or via patterns in the sequencer.

Homepage:
https://www.buzztrax.org/
