SunVox is a small, fast and powerful modular synthesizer with
a pattern-based sequencer (tracker).

As well as its own array of synthesizers, SunVox can record
real-time samples from sound card or other arbitrary input.
It can import tracks from MIDI, XM and MOD files and samples
from WAV, XI and AIFF files. It can export MIDI and WAV
formats and has full MIDI IN/OUT support.

SunVox supports ALSA, OSS and JACK.