MadHelix is a Java Swing-based graphical frontend for SoundHelix, a program which generates music based on entered (or generated) text and plays it back. It is in an early state of development so please let me know of any issues you have with it.
MadHelix is available under the GNU General Public License, version 3 only.
Source code is available on NotABug.
Compiled versions are available from NotABug.