MANY COMMODORE 64 owners have already discovered the virtues of the FM Voice Module, which puts DX9-quality sounds under the control of the home computer for under £100. In conjunction with Commodore's full-size five-octave mechanical keyboard, or even the miniature clip-on Music Maker keyboard, the Module provides an inexpensive introduction to digitally synthesised sounds.

But the software provided with the Module is designed to be simple and entertaining, rather than to allow full control over the FM chips licensed from Yamaha. Now the FM Editor/Composer software package, produced by Music Sales, offers finer control over the sounds.

The program comes in two parts, only one of which can be used at a time due to the 64's memory limitations. The FM Sound Editor has five sub-sections: Setup, Edit Sound, Drum Machine, Fruit Machine(!) and Disk Function.

Setup allows you to choose upper and lower keyboard sounds from the 64 which can be stored in memory at any one time. It's then possible to set a keyboard split anywhere in the five-octave range.

Octave transpose and key transpose are set next, and finally the drum machine function, MIDI In and Out can be switched on or off. More on these later.

The Edit page comes next. This allows you to take one of the preset sounds and edit its FM parameters. However, there's no sign of the multiple DX7-style envelope, operator and algorithm sections you might have anticipated, because again, the program is designed for simplicity. Brightness and volume can be varied from 1 to 255 using a sliding scale, and you can choose one of 255 preset envelope shapes that cover a wide range of styles from percussive to sustained.

The next parameter is Pitch, for each of what are in effect two operators. Altering this can affect the basic "footage" of the sound, create detuning, or cause interesting synchronisation effects, depending on whether the next parameter, FM Link, is set to Simple or Complex. This is like having only two FM algorithms to choose from - pretty limiting. The last parameters are vibrato and tremolo depth for each of the two "operators". Bear in mind that these quantities will be fixed; you can't introduce them as performance effects. Your edited sound can then be named and stored to disk.

The next page, Drum Machine, accesses a very simple real- or step-time percussion generator, with a graphic display of five FM-generated voices - bass, snare, tom, hihat and cymbal. The less said about the realism of these noises, the better. But you can at least run a percussion track while playing the keyboard, and tempo can be set in BPM.

Fruit Machine is a rather smart, randomised display of musical symbols which will generate endless combinations of FM sounds. Just spin the wheels until something you like comes up, tweak it on the Edit page, and save it.

The last page allows you to load new sounds in banks of 64. The disk includes some good strings, electric piano, wind and synth noises, plus a few oddities such as the serialist "Phil Glass" and the elementary "Meatyjob".

You'll either love or hate the FM Sound Editor. If you expect full control over all FM parameters you'll be disappointed, but if you just want to generate a good selection of usable sounds, it should keep you happy for ages.

After producing an on-screen list of the 64 sounds currently available, you can move on to the manuscript page to create your composition with the second part of the package, the Composer.

The main display features two music staves and a series of option boxes at the bottom of the screen. Using the function keys, you can set the time signature (anything from 2/2 to 12/16), key signature, note volume, tempo, transposition, note length, tie type, and bar description (coda, da capo, stop and so on).

Melodies are composed by playing notes in step time on the keyboard, and edited using block copy, delete, insert and erase functions. Sequences consisting of several different monophonic voice parts can be combined to produce finished compositions, which can then be saved to tape or disk.

The FM and MIDI setup page allows up to nine melody parts to be assigned any MIDI channel and switched on or off, and for the clock to be set to internal or external MIDI.

The Music Composer is an idiosyncratic program which, again, will have its fans and its opponents. Considering that the Commodore MIDI interface (without which the FM Voice Expander's MIDI functions are pretty meaningless) has still failed to appear, for the moment the Music Composer is the best option for Expander owners. And at this price, it'll certainly do until something more advanced comes along.

Price £24.99 including VAT

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