Professional multi-track audio recording application

Ardour is a digital audio workstation for recording, editing and mixing
multi-track audio. You can use it to produce your own CDs, mix video
sound tracks, or just experiment with new ideas about music and sound.
Capabilities include multi channel recording, non-destructive editing
with unlimited undo/redo, full automation support, a powerful mixer,
unlimited tracks/busses/plugins, time-code synchronization, and hardware
control from surfaces like the Mackie Control Universal.