A Soundbank contains a set of Instruments that can be loaded into a Synthesizer. Note that a Java Sound Soundbank is different from a MIDI bank. MIDI permits up to 16383 banks, each containing up to 128 instruments (also sometimes called programs, patches, or timbres). However, a Soundbank can contain 16383 times 128 instruments, because the instruments within a Soundbank are indexed by both a MIDI program number and a MIDI bank number (via a Patch object). Thus, a Soundbank can be thought of as a collection of MIDI banks.

Soundbank includes methods that return String objects containing the sound bank's name, manufacturer, version number, and description. The precise content and format of these strings is left to the implementor.

Different synthesizers use a variety of synthesis techniques. A common one is wavetable synthesis, in which a segment of recorded sound is played back, often with looping and pitch change. The Downloadable Sound (DLS) format uses segments of recorded sound, as does the Headspace Engine. Soundbanks and Instruments that are based on wavetable synthesis (or other uses of stored sound recordings) should typically implement the getResources() method to provide access to these recorded segments. This is optional, however; the method can return an zero-length array if the synthesis technique doesn't use sampled sound (FM synthesis and physical modeling are examples of such techniques), or if it does but the implementor chooses not to make the samples accessible.