The BBC Micro itself has much to offer the music enthusiast but it also forms an ideal base for the addition of more sophisticated hardware. We look this month at some of the delights now available to tempt the serious user.

At more than the price of the Beeb, the Clef Music System has to be something special. It is. It is a complete music system with synthesizer, keyboard, and software ready to plug into your BBC micro for studio or stage work.

The normal method of sound synthesis used on cheap synthesizers is to produce a waveform rich in harmonics, like a square wave, and then filter out the unwanted overtones to produce the required sound. The Clef system tackles the problem in a different way. Sounds are created by programmable digital - oscillators capable of producing any wave shape. 32 sound generators are available, each with its own programmable envelope and keyboard touch sensitivity. Up to 4 sound generators can be assigned to each voice, giving a minimum of 8-note polyphony available on the 61 note (5 octave) keyboard included.

Software is provided on both disc and ROM. Once the software is loaded from disc the keyboard can be played, and different preset instruments selected. One problem is that the keyboard has to be turned off before an instrument can be changed. 18 different voices are available using the keys 1-9, and Shift 1-9. I wonder why the function keys haven't been used? Nevertheless the default set of sounds is not at all bad, if a little unimaginative. Pieces can be recorded in 'real-time', and then played back instantly with all dynamic and pedal variations included. They can then be stored on disc for later recall.

Selecting 'M' displays the menu options, the first of which is the boot-up option. The second enables any of the sounds to be completely altered by changing the number of oscillators, the waveform, the fairly comprehensive envelope parameters, touch sensitivity, sustain pedal etc. Any voice with altered parameters can then be filed as a new instrument.

The third option involves creating new sets of instruments, to provide almost limitless numbers of voices, at least in theory. This sub-menu also gives a hint of further goodies to come, because selecting one option (new table creation) produces the message 'Not yet available', and a return to the menu!

The fourth option enables waveforms, the very stuff of voices, to be manipulated or new ones created, which can then be filed and loaded as new waveform sets. There are 16 waveforms stored in the ROM which cannot be altered, and a further 16 that are modifiable. In addition the four 'primary' waves of sine, square, triangle, and sawtooth can be selected and added. Error trapping should be better here, because if a waveform is selected, stupidly, with an initial amplitude of @ a 'division-by-zero' message appears and the program has to be re-run.

A graphics display of the waveform is produced and any harmonic up to the 25th with a relative amplitude of 1-100 may be added, with the result automatically redrawn. The 'Analyser' option enables any waveform to be analysed to give a listing of the harmonic content.

The possibilities are badly limited by the software at present available. The most glaring omission is that the system does not give track-on-track recording with editing facilities, different voice for each track etc. The musical possibilities should be exciting, but aren't, because of the software limitations. In terms of hardware I expect a much better finish for a system at this price. The wood-grained effect on the cabinet looks cheap, and doesn't do the concept justice. The output is in the form of two jack sockets for connection to a stereo amp - yes, it's stereo - and the sound quality is acceptable, but doesn't match synthesizers in the same price range. There is too much output filtering, causing the sound to be rather muffled and lacking in bite.

The software flows nicely from one menu to another and a group of children soon worked it out without the benefit of the instruction notes, which are very poor. The musical examples would also benefit from being played better and more accurately. The system is an interesting development and one well worth closer investigation by those wanting to produce decent musical sounds with the computer, and who have developed beyond the internal sound chip! However, as other similar systems are bound to come on to the market, each learning from the mistakes of its predecessors, Clef will have to update and improve to stay competitive.