When Acorn launched the Electron it is probably true to say that no-one envisaged it being used as a music system. Much less, I'm sure, did anyone suspect that it would, one day, be at the centre of a digital synthesiser complete with programmable instruments, a computerised mixing desk, stave editor and its own MCL (Music Composition Language).

Well now, thanks to the efforts of Hybrid Technology and Pres, it is.

The Hybrid Music System was originally developed to run on the BBC Micro and it is now available for the Electron. Happily however, it is not a cut-down version but a full-scale implementation of the system, with only one or two functional differences which we'll look at in a moment.

The first thing you need - apart from the Hybrid Music System itself - is a couple of interfaces. You'll need the Pres AP5 interface and an &E00 DFS, plus a disc drive. You also need suitable amplification. You can listen to the system through your hi-fi or even through headphones, but the output is in stereo so a hi-fi system will give you the best results and is much recommended.

The system runs under a new language called Ample (Advanced Music Production Language and Environment). The Ample rom plugs into the AP5's internal rom socket and a ribbon cable from the hardware box, which contains all the synthesiser bits, plugs into the 1MHz bus. As the software is rom-based, it doesn't use precious memory, although modules must be loaded from disc (modules coming up) as required, the same procedure as is used with the BBC Micro version.

The box containing the hardware is exactly the same as the BBC Micro unit and the manual is the one supplied with the big brother version. An additional two-page leaflet describes the differences between the systems, and these are quite minor.

Operation is exactly as described in the User Guide except for some differences in display and the keyboard. For example, you must press CTRL-I instead of Tab, and Func as a key for the function keys - but Electron users are used to doing that now. Four other key substitutions must be made, too.

The BBC Micro version uses Mode 7, whereas the Electron uses Mode 6 with a consequent lack of colour. In the Staff Editor this results in horizontal lines which divide the display. It's still perfectly useable, if a little odd.

Having booted up, you are presented with the front end of the system called the Studio 5000. From here you can enter any of the three main modules - the Mixing Desk, Staff Editor and Notepad - as well as loading and saving programs, although all this can also be done from the other modules.

The first thing you'll want to do is load and play the set of demo programs. Pressing f9 loads a Juke Box which makes selection simple and easy. Some of these pieces are extremely impressive.If you have ever cocked an ear at Hybrid's stand at the Electron And BBC Micro Shows you'll know what I mean. After being suitably impressed, you can go back to the Studio 5000 menu and work your way through the modules.

Before taking you on a guided tour, it's worth saying a few words about Ample, because it really is the heart of the system - although it will often be transparent to the user. The basic user is the word, and words can contain anything or be defined to do anything. For example, a word can contain a riff, a chord sequence, an instrument definition or it can call up an action such as a tempo change.

Words can be defined in terms of other words, and there will eventually be a single word at the very top of your program which will start all the music lines playing at once.

Operations are stack-based and Ample syntax is similar to the postfix notation used in Forth. If you're not a postfix fan, however, don't let that put you off because the system is quite easy to understand and use. No stack use is necessary except for advanced programming. In normal use you simply put the number before the word, for example, 6 MODE, "filename" LOAD, 8 VOICES, and so on.

Language buffs note: Ample is a complete language - in fact, the Studio 5000 software was written largely in Ample. We lesser mortals can simply use the music parts of the language to produce music.

As well as supporting traditional notation, Ample contains its own music composition language (MCL) which is ultimately more flexible and versatile; more of this in a moment. Hybrid has designed the system and software to be fully expandable, and new features can be used simply by installing new software modules.

Time to open the User Guide. It is excellent and leads you gently through the system. The first module it describes is the Mixing Desk and we'll follow suit and do likewise.

This screen displays a mixing desk console. The system generates 16 sound channels which are normally paired to produce eight two-channel voices, although you can use all 16 on one voice if you wish. The mixer has eight channels - one for each voice - complete with faders, stereo positioning (pan pots) and volume meters.

The instruments playing on each voice are shown above the pan pots. Pressing Shift clears the bottom half of the screen and gives you a list of available instruments which can be selected with the cursor keys. Releasing the Shift key will transfer that instrument to the mix.

Changing instruments on a voice can take place while the music is playing so you can hear how the piece sounds as you make alterations. This concurrency is an important part of Ample and you'll find you can alter most parameters while music is playing.

You can pan a sound through seven stereo positions, transpose the piece and alter the tempo. When you've produced a mix you like, type MAKE and the system will automatically produce a word containing all the settings. You can produce several different mixes or sub-mixes and use them at any point in the music.

You can pause and fast forward the music and you can step through it a beat at a time. Many of these features are only possible with a computerised system.

The next module in the book is the Staff Editor. This supports the full range of notes, rests and accidentals along with slurs, triplets, duplets, dots and ties. You don't have to use bar lines but if you do the system will automatically check the length of each bar. You can define the on-time of the notes to produce legato and staccato phrasing, and can include dynamic (volume) and accents.

Chords can be entered too, although the notes are staggered across the stave rather than appearing vertically. Coupled with the horizontal lines, it does give a rather broken appearance to the screen, but it is quite easy to adapt to.

You can program non-standard key signatures and define words relating to performance expression. You can also produce percussion patterns on the treble clef.

The Staff Editor is ideally suited to anyone working with traditional music and perfect for copying traditional music scores from sheet music.

More than that, however, the system can translate the music you produce on the stave into Ample's MCL in the Notepad. The Notepad brings you nearest to the Ample ideal. It is a screen-sized text editor which can be used to produce music or to create or edit instrument sounds

Ample music notation is very simple. Notes are called by their usual names, A to G, and the duration and octave are determined by initial numeric settings. Upper case letters indicate a rise in pitch from the last note and lower case letters represent a fall in pitch.

Notes can be lengthened either by specifically increasing the duration or, more usually, by putting a slash character (/) after the note. Here's the first four bars of Good King Wenceslas:

24, 0: CCCD ccg/ AaAB C/C/

The first figure, followed by a comma, sets the beat length and the next figure, followed by a colon, sets the octave.

This notation is, arguably, easier to understand and more logical than traditional notation. It supports chords and the full range of accidentals, and because it is text-based it is fairly easy to manipulate notes and music with programming techniques such as loops.

This can lead you into an absolutely fascinating area of music, that of applying computer power to the composition process. It's not too difficult and I have produced several pieces of computerised music, some of which have been described as Tangerine Dream like.

Ample also provides elements that are not included in traditional staff notation such as negative notes - going back in time for pickups - and strummed chords. It has built-in special effects, which can also be used on the stave, such as Echo, which can be used to create reverb effects and true echoes. These can be detuned, transposed and panned across the stereo image.

Continuous changes in tempo and volume are very rare indeed in computer-based music but they are standard fare in the Hybrid Music System. They can even be used to produce autopanning and slide effects.

You can edit words in the Notepad which were created in the Staff Editor and the Mixing Desk, and this is really the module on which the other modules hang.

The Notepad is also where instruments are designed and edited. Switching to Panel Mode allows you to edit instrument characteristics by moving the cursor between different parts of the instrument's parameters. As in the Mixing Desk, selection of waveforms, for example, is made by holding down the Shift key and a list of options appear at the bottom of the screen.

You can choose from 14 waveforms, 17 amplitude envelopes and 17 pitch envelopes. You can add synchronisation and ring and frequency modulation too.

A unique facility is the ability to design your own panels. You could call up an unmodulated piano sound and type in controls for frequency modulation, ring modulation and so on, in any spare area of the panel. The limited number of waveforms and envelopes is not as restricting as it may at first appear.

The ease of instrument creation helps offset any twinge of regret you may feel about not having full programmability. It would be easy to add an additional waveform editing module to the system and rumour has it that one is currently under development.

The manual contains graphic displays of all the waveforms and envelopes, which are extremely helpful. The system loads with 14 preset instruments and the manual contains details of another 25 for you to type in. You'll get lots more from the demonstration pieces too.

If you want to delve even deeper into the system, watch out for the Programmer's Guide. A leaflet points out the two main functional differences between the Electron and BBC Micro versions of the system. As the Electron version runs in Mode 6, there is consequently less memory for program storage. Also, as the Electron has less processing power operation of controls and execution of programs is generally slower. This is most evident with programs requiring lots of processing, and the use of Echo can cause a hiccup or two as well.

However, the majority of BBC Micro Ample programs will be compatible with the Electron system, and Electron users can tap into a wide source of programs and assistance in the form of Ample user groups and bulletin boards.

Hybrid is looking at the compatibility of existing BBC Micro Ample music albums (on floppy disc) with the Electron system and will be supporting the Electron system with its own Ample albums. There are provisional plans to release a keyboard - the Music 4000 - which will allow users to play the system as a synthesiser and enter music into it in real time. There's also the possibility of linking with other units such as a Midi interface.

Hybrid has developed an amplifier called the Music 1000 with three headphone outputs which is ideal for use in the classroom. This is, of course, compatible with the Electron system.

Now at last Electron owners have a music system available for their computer. The combination of a synthesiser with programmable voices, stave editing, a mixing desk plus the computing power of the Ample language makes this system unique. There's really nothing to compare it with.

Not one other personal computer - other than the BBC Micro - has such a fully integrated music system. It has simply got to be one of the best and cheapest ways into computer music. If you want to hear it in action send for the demonstration cassette. You'll want one!