The term MIDI stands for Musical Instrument Digital Interface. Do not confuse it with the term midi as applied to hi-fi units, which is a description of their size (midi as opposed to biggi). MIDI is what is known as a serial connection. The data are sent as a series of long and short pulses in groups of eight. Additionally there is a pulse on either side known as ‘start’ and ‘stop’ bits. Just over 30 000 of these pulses can be sent every second – 3000 ‘groups’ known as ‘bytes’ (31.25 kbaud in tech-speak). Figure A3.1 shows the difference between audio and MIDI connections.