MusE is a multitrack virtual studio for Linux that has support for sequencing of both MIDI and audio and has, among other things, support for LADSPA, Jack and ALSA.

Some Highlights

• Advanced jack audio routing possibilities.

• Automation architecture for both MIDI and audio.

• Better MIDI controller abstraction: available MIDI controller can be defined in instrument definition file (*.idf).

• Integrated mixer with:

  • Unlimited number of inputs.

  • Unlimited number of outputs.

  • Unlimited number of tracks.

  • Unlimited number of aux's.

  • LADSPA effects on all track types, both before and after fader.

  • Stereo/Mono track types.

• interface changes, the TrackInfo pane is used more.

• MIDI instrument definition files (*.idf).

• Lots of customization options.

• Shortcut editor.

• Drag and drop import of MIDI files.

• Drag and drop import of wave files.

• Standard MIDIfile (smf) import-/export.

• RTC (Real time clock) use for rock solid timing.

• Advanced arranger with track and part abstractions.

• MIDI editors:

  • Pianoroll.

  • Drum editor.

  • List editors.

  • Controller editors.

• Realtime editing of "everything".

• Unlimited number of open editors.

• Unlimited undo/redo.

• Realtime and step-recording.

• Multiple MIDI devices.

• Unlimited number of tracks, both MIDI and audio.

• Audio playback/recording.

• Sync to external and internal devices/applications:

  • MTC/MMC.

  • MIDI Clock.

  • Master/Slave.

  • Jack transport enabled.

• LADSPA effects.

• Integrated softsynth architecture M.E.S.S

  • Several internal synths available.

  • Simple architecture for adding more synths.

  • support for industry standard Windows VSTi softsynths.

• JACK enabled.

• ALSA sequencer client.

• LASH enabled (formerly LADCCA).

• Raw MIDI device usage through ALSA.

• XML based project files.

• XML based configuration files.

• project file contains complete app state (session data).

• Application spanning Cut/Paste Drag/Drop.

• uses C++, QT3.2 GUI Library, STL.

And the most important feature for a free application:

• GPL Licensed.