Just picked this up on Linux Journal. Reviews of the best Midi apps for linux from the ubiquitous Rosegarden to seq24. The power of rosegarden has always impressed me. It supports Disposable Software Synth Interface (DSSI) and the LADSPA audio processing API enabling a wide range of plugins to be added (or even developed).. As a composition tool, it's usefulness is enhanced through support for the Lilypond notational format, it's pretty much the complete midi sequencer. If you're serious about music but not so big on linux then tough it out. Rosegarden is one of the reasons why I love free software.