jMusic provides a library of classes for generating and manipulating music, and is a solid framework for computer assisted composition in Java. jMusic supports composers by providing a music data structure based upon note/sound events, and methods for working with that musical data. jMusic can read and write MIDI files, audio files, and its own .jm files. jMusic is designed to be extendible, encouraging you to build upon the functionality of jMusic by programming in Java to create your own music composition tools.
jMax is a visual programming environment for building interactive real-time musical and multimedia applications by allowing the user to interactively design dataflow circuits. The basic data types that can go through are integers, symbols, lists, etc. It is an event-driven system and has been used for MIDI processing. A second part of the system (DSP) allows a continuous signal to flow through a circuit, which is most useful for PCM sound (ie. microphone, sound files, etc.). The system is extensible by using shared libraries, you may add data processor types, data types, GUI elements, device types, and more. Data processors may also be designed as circuits and reused.
Javasynth is a Java-based system for creating (rather experimental) modular audio systems called sound modules. This allows synthesizers of some kind to be assembled in a modular fashion using oscillators, amplifiers, envelopes, filters, and other components familiar to those that have worked with hardware synthesizers. It includes a separated synth engine and a Swing user interface for building sound modules.
orDrumbox is a fully-featured drum machine and audio sequencer that is pattern oriented, has an automatic composer, automatic sound assignations, custom drum kits, loop support, and the ability to import and export songs. Its main features are a pattern seqencer, a drumkit editor, a piano roll, a step sequencer, sound generation, soft synth, and the ability to import and export MIDI files and Wave files.
bcr beats is a beat slicer that lets you cut up and play with an audio sample: you can trigger slices and loops with MIDI or the mouse and keyboard, set pan, volume, and sample rate values, and generally have lots of fun. The interface is based on the Behringer BCR2000 MIDI controller, which means lots of knobs. It can be used with or without a controller.
bcr harms takes a model of the quantum harmonic oscillator and adapts it as a soft synth. It lets you hear and see how the oscillator wave functions evolve in real-time as you modify amplitudes and other parameters. The user interface is based on and integrates with the BCR2000 MIDI controller, but the application can be used without a controller.