The Hybrid Music 4000 is a four octave keyboard which allows you to play the sounds and record sequences directly. It is part of the Hybrid Music System for the BBC model B, BBC B+ and Master. 

The Music 4000 connects to the BBC Microcomputer's User port.

It complements the versatile Music 5000 synthesiser, which uses a system known as Ample for music notation and control.

You also need:

• BBC Micro Model B, B+, or Master 128, with Acorn-compatible disc drive
• Music 5000 Synthesiser (or Music 500 with Music 5000 software), installed and tested as described in its own Installation Guide.
• Audio amplifier system, with audio lead to the synthesiser unit
• One blank formatted disc

The keyboard is fully polyphonic and greatly enhances the way in which the user can interact with the Music 5000 Synthesiser and software suite as it is "always on" so can be played regardless of the software's current context.

The keyboard also supports the use of a sustain pedal using the 6.3mm socket.

Together with Hybrid Music 5000 this keyboard was kindly donated by David Barton.