Few companies have entered the field of computer music - in both domestic and professional fields - as wholeheartedly as Siel, an Italian company whose most impressive product three years ago was a string synthesiser. The parent company's British counterpart - Siel UK - has also got into micro music in a big way. Not only are they selling the complete range of Italian-designed MIDI software for the Commodore 64 and Spectrum, they've also modified both hardware and software to work with Britain's most popular home micro, the BBC B. And, as if that weren't enough, they're taking on music retail distribution for the two more domestically-oriented programs reviewed in Software Surplus - Commodore's Music Maker and Island Logic's Music System.

Over the last couple of weeks, I've spent some time in the company of two of Siel's packages for the Sinclair Spectrum, namely the Expander Editor and MIDI Live Sequencer. Both of these are designed to work in conjunction with Siel's own MIDI interface, which is identical to that used by JMS and has already been described in detail within these hallowed pages.

My overriding impression is that, if their Commodore and BBC packages are in the same league (and given the additional possibilities afforded by those computers, there's no reason why they shouldn't be better still), Siel have got very little to worry about.

Expander Editor

Siel's stand-alone MIDI Expander was one of the first such devices to appear - now the marketplace is full of them, from manufacturers as diverse as Yamaha, Korg, Oberheim and Roland. The idea behind all of them is that by buying one, you at least double the capabilities already afforded by your existing MIDI synth, and you don't have an extra keyboard to pay for.

The Expander is designed specifically for use with Siel's own Opera 6 polysynth and its immediate successor, the DK600 (reviewed elsewhere this issue), and since it employs digital parameter control for patch editing, one of these is essential if you're going to make proper use of the additional facilities it offers. Even then, editing isn't exactly a barrel of fun.

Or at least, that was the state of play before the arrival of Siel's Expander Editor program.

Briefly, what the program does is to display the Expander's controllable parameters graphically on the micro's monitor screen, with a key beneath that tells you how to access each parameter using specific keys on the Spectrum's QWERTY keyboard. In fact, each display represents a section of the DK600's front panel and the layout is identical, so if you're already acquainted with the DK, finding your way around the Expander Editor should be the technological equivalent of a piece of cake.

Dialling up Patch 95 followed by Record and Enter on the Expander enables hardware to communicate with software, though no confirmation that dialogue is taking place becomes apparent until the message 'OK, Data received' comes up on-screen. First time round, that's a very reassuring line to read.

There are four graphic displays in all, and these represent the LFO (accessed by selecting '1' on the Spectrum), the DCOs (2), the VCF (3), and the ASDR (4).

So much for the numbers. The QWERTY's letters allow you to do various things with a parameter screen once it's been selected. Amongst many other things, you can gain access to either the old setting (O) or the new one (N) for a particular parameter, play either a chord (C) or a monophonic sequence (M) that's pre-programmed to illustrate a selection of pitches in the patch you're editing, load from the Expander (L), dump in a new program (D), or turn to the software's Help Page (H) which guides you clearly through what each function is, what it does, and how you can go about altering it.

In addition, the Spectrum's arrow keys are used to move a bright rectangle around the display to affect individual editing units, keys R and T are used to increment pot values in steps of 1 (or steps of 10 if you hold the Caps key down), while S switches those parameters that are simply either on or off.

How does it work out in practice? Well, the comprehensiveness of the display and the easy-to-remember commands make the whole process hugely entertaining as well as useful. As you press R to increase a parameter value, a little indicator moves round the 'knob' in an approximation of where the real thing would be, while the value displayed inside the control increases simultaneously. Switches have light and dark patches to indicate whether they are on or off, and react instantly to any press of the S key.

This is probably the best sound editing program I've ever seen. It's extremely effective, user-friendly, and makes using a home micro a pleasure rather than a chore. At an RRP of £53.50 for the Spectrum version, it seems excellent value for money, and it liberates the Expander for use with MIDI synths other than the Opera 6/DK600. So well done Siel for not letting commercial considerations get in the way of a terrific piece of software.

Live Sequencer

Like the Expander Editor, Siel's Live Sequencer program for the Spectrum is cassette-based, and allows the recording of a single polyphonic sequence and its subsequent speeding up and slowing down on playback. The sequence can also be looped to play continuously, should you be very enthusiastic about your composition (or anyone else's, for that matter).

The program loads quickly and easily. As Spectrum owners will know, the procedure is... LOAD (the keyword on the J key), followed by SYMBOL SHIFT and P... twice, not J twice as it says in the manual. You're kept well informed while the program is loading, and the screen display (there is only one) appears once the process has been completed.

The display comprises a menu that lists six available options as follows. Play, somewhat confusingly, actually enables you to record your sequence, and is operated by pressing 1 and Enter. Once you've finished playing, pressing Break returns you to the original menu, where the Memory Used message should contain a percentage of storage capacity taken up by the sequence: if this still shows 100, your sequence hasn't been recorded - start again.

The sequence is replayed using the second menu option, Playback. Whichever MIDI keyboard you're using remains usable for additional performance, though as no overdubbing is possible with this software, only the original sequence will remain stored in memory. Tempo control is also effected in this mode, key 5 slowing the track down and key 8 quickening it up.

The remaining four options are Load from Tape and Save to Tape, which are pretty self-explanatory, Correct Time, which resets a post-performance tempo adjustment so that the sequence is replayed at its original speed, and Refrain, which is Siel's equivalent of a loop.

This software package is exactly what it purports to be - a real-time entry sequencer that faithfully records, stores and replays any sequence you care to put into it, so long as it's not of gargantuan length. It's easy to use and well-presented but, for obvious reasons, rather limited. I kept on wanting to overdub further sequences as the inspiration took me, despite the fact that such feats are impossible on the live Sequencer.

Still, at £22 I don't think there can be any complaints, and this package would make an ideal starter program for someone just getting into computer music via a MIDI synth and Siel's interface. Which, as chance would have it, is exactly how the Live Sequencer is being marketed...

Further information: Siel UK, (Contact Details).