Advanced Gtk+ Sequencer audio processing engine

 Advanced GTK+ Sequencer is intended to be used for music composition.
 It features a piano roll, as well as a synth, matrix editor, drum
 machine, soundfont2 player, mixer and an output panel. It’s designed to
 be highly configurable. You may add effects to its effect chain; and
 add or remove audio channels/pads. You may set up a fully functional
 network of engines, thus there is a link editor for linking audio lines.