Rosegarden is an attractive, user-friendly MIDI and audio sequencer, 
notation editor, and general-purpose music composition and editing 
application for Unix and Linux.

The only documented hard dependency of Rosegarden is fftw, so it *must*
be installed.  Jack-audio-connection-kit is documented as an optional
dependency, but testing here indicates that it must also be installed.
liblo, liblrdf, and ladspa are optional dependencies; they will be used
if they are available at build time. LIRC is another optional dependency;
if you want lirc-support, you will have to pass LIRC=yes to the script.
Further rosegarden makes use of xml-twig and lilypond at runtime.
All dependencies (required and optional) are available at SlackBuilds.org.