In terms of sheer numbers, Hybrid Technology's computer music system for the BBC micro outsells any other music software package on the market. Ian Waugh finds out why.

Eavesdrop on any group of musicians talking hi-tech and the chances are that computers will figure prominently in their conversation. You'll hear tell of the ubiquitous Atari ST, the not-so-ubiquitous but ultimately more flexible Amiga, and the IBM PC - or more likely an Amstrad clone. If someone says "Apple Mac" you're listening to a pro or an amateur with a well paid job! But unless Vince Clarke is present, the BBC micro is unlikely to figure in the discussion.

One thing all these systems have in common is MIDI. They are all used to run software-based MIDI sequencers and voice editors. Including the BBC micro.

Conversation is likely to revolve around the number of tracks a system has, real-time versus step-time input, the number of MIDI filters, editing facilities (is it note level only or does it go down to event level?), and a few bods may venture to expound on the ease with which System Exclusive messages may - or may not - be sent from their computer to their instruments.

But if you have a BBC micro there is an alternative way to make music - the Hybrid Music System. This is a computer-based music system as opposed to the MIDI-based systems described above (the difference will become clear in a moment). If you want to know more about it, a good place to start would be the January 1987 issue of Sound On Sound, which featured a review of Hybrid's Music 5000. If that issue has escaped you, here's a brief overview.

HYBRID MUSIC SYSTEM

At the heart of the Hybrid Music System is the AMPLE Nucleus ROM. AMPLE stands for Advanced Music Production Language and Environment: it's a programming language specially designed for music making and one of its main features is concurrency. This is the ability to do more than one thing at the same time, allowing music parts to play together. Once the music has started playing control returns to command mode so you can enter further instructions on-the-fly.

The sounds are produced by a 'black box', the Music 5000, which is the basic module of the System. Actually it's not a black box, it's a beige, BBC micro-coloured box and, under software control, it can play eight different voices at the same time.

Since the review of the Music 5000, Hybrid have released the Music 1000 and Music 4000, a four-octave keyboard which can be used to play the Music 5000's voices just as you'd play a synth. It can also be used to record music in real-time and step-time. The software has six built-in effects including Transpose and Expand (this can transform a single keypress into a programmable arpeggio, chord or echo pattern).

The Music 1000 is an 8-watt stereo amplifier with three headphone sockets, designed with an eye to the educational market but also suitable for powering bookshelf speakers.

As a musician you may well shy away from anything which requires computer programming but the Hybrid Music System uses a number of front-end modules which let you create music without getting involved in any programming. Music can be entered on the stave in the Staff Editor or in a word processor-like Editor called the Notepad using AMPLE's own simple MCL (Music Composition Language).

Whichever method you use to enter the music, it is all stored in the same internal format. You can even display real-time recordings on the stave, although the presentation is that of single notes (none are beamed) and stepped chords. There are two main drawbacks to this System - you are restricted to the sounds the Music 5000 is capable of producing, and you only have eight voices to play with.

THE MUSIC 2000

Enter the Music 2000 MIDI Interface... It's another black, sorry beige, box with three MIDI Outs and one MIDI In. There are three LEDs on the front which flash when data is being transmitted. It connects to the Music 5000's 1 MHz extension socket and has an extension socket itself so that you can daisy chain even more items to the 1 MHz bus. Another cable plugs into the BBC's power supply and it, too, has an extension which you can use to power a disk drive, for example.

The controlling software takes the form of a software module, M2, which loads automatically when you boot the system. It adds several new words to the language (see side panel) and we'll look at them in turn in a moment.

With the Music 2000 the number of voices available to you rises dramatically from eight to 32, and a musical arrangement can consist of up to nine parts each with up to 12 voices (bearing in mind the 32-voice limit). Of course, with MIDI, you are now no longer restricted to the sounds the Music 5000 is capable of producing.

As anyone who has dabbled with MIDI will know, there is a vast difference in MIDI implementation between instruments. There is, however, a set of common MIDI functions which all instruments must support. These include Note-On and Note-Off messages for synthesizers and expanders, and MIDI sync facilities (such as the System Real Time messages, Start and Stop) for sequencers and drum machines.

The Music 2000 makes it very easy to implement these common functions - almost plug in and go. For example, voices are sent to MIDI through 'mix' words. An example mix is supplied on disk for you to load into a program and it's quite a simple task to re-route voices horn a Music 5000 piece to MIDI instruments by editing the mix word. The more advanced operations (the not-so-common functions) can be accessed and controlled by the new words. Time for a closer look.

MIDI WORDS

You can do an awful lot with only four words. 'MIDIV' is the instruction which makes the current voice a MIDI voice. Any voice in a Music 5000 piece can be replaced by a MIDI voice - even on the fly - by entering, for example:

1 SHARE MIDIV

'MIDICHANNEL' selects the channel number, no problems there. 'MIDILINE' selects MIDI Out sockets 1, 2 or 3, and 'MIDIPROGRAM' makes a patch change. No problems there, either. Here's a complete example:

5 SHARE 4 VOICES MIDIV 2 MIDILINE 3 MIDICHANNEL 19 MIDIPROGRAM

This instruction would assign four voices to part five and transmit them on MIDI channel 3 through MIDI Out 2, selecting patch number 19. Music lines can be sent to the Music 5000 as well as MIDI, so you can mix the two sound sources. Obviously, the MIDI voices do not appear in the Mixing Desk but you can mix Music 5000 voices as usual.

All the elements of standard AMPLE notation are reproduced by MIDI voices, bar a couple of exceptions. Firstly, loudness is expressed as key velocity, so the instrument must be velocity sensitive if the effects are to be heard (all Music 5000 voices are 'velocity sensitive'). Secondly, MIDI does not cater for slurred notes - the slur will be alien to many keyboard players - and so they are ignored (the Music 5000 can handle them, however). A further problem may arise if you try to play two notes of the same pitch, as MIDI doesn't cater for this either and, again, this is impossible to play on a keyboard. The response will vary from instrument to instrument but the manual suggests ways around it should it cause problems.

AMPLE takes all these things in its stride and it's important to realise that the deficiency lies with MIDI, not the Hybrid Music System.

REAL-TIME CONTROL

Just as 'MIDIV' assigns a voice to MIDI, so 'MIDIRT' makes the current voice a 'real-time voice' which sends clock Start and Stop messages. A Start is sent by sending an X, the AMPLE word for a hit. Stop is represented by a rest(). A second X sends a Continue message. Music parts can easily be defined to start and stop a drum machine - or sequencer - at any point in the music.

One of the most fascinating aspects of the Music 2000's real-time control is the way external units follow changes in tempo. AMPLE users will be used to programming rallentandos and accelerandos (some sequencer software lets you do this, too) and connected drum machines will follow all tempo changes. Most drum machines cannot perform tempo changes themselves. Even more interesting is the ability to programme a fermata (a musical pause) to pause a drum machine. This would be very difficult, if not impossible, to achieve with most sequencers.

Using 'MIDIOUT' or 'MIDIWORD' you can define words to act as Song Position Pointers - the manual includes several examples. There are also words which will make a drum machine play a series of patterns in a particular order - useful, perhaps, if you are experimenting with the length or order of musical sequences.

The percussion sounds on a drum machine respond to particular MIDI note numbers. You can use these to create a rhythm part to send direct to a drum machine. You don't have to think in terms of note numbers, though, because the manual thoughtfully includes words which let you create patterns on a drum grid similar to those used on Roland's TR505 and TR626.

You may also be able to programme a greater range of dynamics than those available from the front panel. Many drum machines respond to velocity information over MIDI but you may only be able to programme, say, two levels from the front panel - normal and accent. 'VEL' can be used to balance a drum kit, or any other voices which are velocity sensitive.

As the Hybrid System is fully-integrated, you can use the Music 4000 keyboard to play voices on an expander. The software module contains a keyboard control panel which can be customised to call up any number of presets. In fact, the nature of AMPLE lets you define any patch with only one word. For example:

"lead" [ MIDIV 1 MIDILINE 4 MIDIPROGRAM ]

You can also define words to select voices on a synth with banks. The manual includes a word to do this on the Roland Juno. For example, entering 2 3 1 junoprog would select patch 2, bank 3 and group 1.

You can use the keyboard to record music in real-time or step-time in typical sequencer fashion. As a real-time sequencer, the System works very well and it even has a quantisation option. You are limited by the BBC's memory, however, and the System wouldn't take too kindly to a long meandering piece. The normal method of constructing music is to build it up in sections, rather like pattern-based sequencers.

Although the keyboard lacks pitch bend, velocity sensitivity, aftertouch and modulation, all these can be edited into the music later (more about this in a moment).

MUSIC CREATION

Many people produce music on their Hybrid Music System solely with the keyboard. This is ideal if you are more comfortable playing than using music notation (either AMPLE or the traditional sort). I must confess a preference for step-time input and the greater control it gives you over your music, and this is ideal, too, for users without any technical expertise.

The range of 'music construction' options are greater on the Hybrid Music System than on any MIDI-based system. Because the system is computer-based, you can perform programming functions on music lines. For example, loops, transpositions, IF/THEN constructions, tempo changes, random factors and so on.

The editing is infinitely more precise, too, at note level and at event level. Instructions can be altered by redefining a word or changing a parameter.

AMPLE PROGRAMMING

Since we've touched upon programming, let's look at it in more detail as this is undoubtedly what makes the Hybrid Music System so powerful. And for two reasons. Firstly, it allows you to construct and transmit virtually any MIDI message. Secondly, it allows you to do it with only one command. One word can call up a patch on any instrument, it can configure your entire MIDI system for a particular application and it can reset a drum machine.

As well as the Note-On and Note-Off commands of common MIDI, the Music 2000 software includes several words specifically to control functions such as pitch bend and channel pressure. These are listed in the side panel.

'MIDICHPRESSURE' sets the amount of key pressure effect to be applied to the notes on the current voice's channel. This is the most common form of aftertouch supported by MIDI instruments but if you have an instrument which responds to aftertouch on individual notes (Ensoniq SQ80 and EPS for instance), 'MIDIPRESSURE' will send pressure information to just one note.

'MIDIBEND' determines by how much a note is bent and the amount can be set to match the pitch range of a particular instrument. You can even programme a word to produce a glissando instead of a bend. Triggering pitch bend by an instruction means you don't have to store masses of pitch bend data (which otherwise eats up memory) and you can make sure the bend is exactly the amount you want.

'MIDICONTROL' controls the MIDI controllers as you would expect. The manual includes words which define simple modulation and sustain controls. There is also a word to test an instrument's response to controller messages and a word allowing you to use a joystick as a controller to add, for example, pitch bend. This could be used to change tempo or trigger some other form of user-interaction.

'MIDIOUT' and 'MIDIWOUT' send a byte and a word (two bytes) over MIDI. Between them they allow any MIDI message to be transmitted, although you will have to dig a little into your instruments' manuals to extract the necessary data. These words are used in the Song Position Pointer definitions and the manual includes simple words allowing you to send System Exclusive messages.

MIDI IN?

You may have realised that we haven't mentioned the MIDI In socket yet. It's there for a purpose as Hybrid Technology re-designed their interface in the late stages of its development specifically to include it. Unfortunately, it is not mentioned at all in the User Guide and there are no high-level words to support incoming MIDI messages.

This means two-way communication in programs such as voice editors is out, as is the analysis of messages in MIDI monitoring programs. It will also be especially disappointing to anyone who owns a MIDI keyboard and was hoping to use it for real-time recording. I'm afraid you can't.

Essentially, this means that the Music 2000 must always be the controlling system and cannot be controlled by an external drum machine or sequencer. It has no sync-to-tape facilities either, so you can't multitrack with a single synth or expander. If you want to use the system for purely MIDI purposes, you must also buy the Music 5000 - which I'm sure you'd find a use for, anyway.

It's doubtful what, if any, support Hybrid Technology intend to give to the MIDI In in future, although I believe some enterprising users have written their own machine code patches to make use of it.

The User Guide is in two parts. The Tutorial section takes you through the operation of the System and the Reference section contains a detailed description of the new words. It is littered with example definitions and suggestions for further applications. It's clear and well-written and many of the examples are sufficiently well documented for you to modify on your own (perhaps with the help of the Music 5000 Guide). Having said that, more details would be nice, especially with regard to the more advanced applications. If you want to go further, the AMPLE Nucleus Programmer Guide is essential reading.

Taking power and flexibility to their ultimate conclusion, the Music 2000 would let you assign each voice to a different MIDI channel (and line) and give each note its own sound, volume level and set of controls (pitch bend, etc) - even the individual notes making up a chord.

I know there are musicians who will drool over the prospect but you do not have to use the System to this level of precision. The Hybrid Music System is very easy to use on a superficial level and you can investigate its more powerful applications as and when you feel the need.

IN CONCLUSION

Because of its association with home users and its widespread use in education, some musicians have wondered whether the Hybrid Music System is a pro system. Well, if you mean 'is it used by professionals?', then the answer is yes. Tim Souster, who wrote the Hitchhikers Guide To The Galaxy music, wrote a piece entitled 'Work' for piano and the Music 5000. Patrick Gowers used the 5000 and 2000 to create music for the TV series Sherlock Holmes. If you mean 'is the System capable of professional results?', then the answer is still a resounding yes. It is a far more powerful MIDI controller than any existing computer-based sequencer.

Power is the word, and now I hope you can see the difference between a MIDI-based system and a computer-based one. There is really nothing like the Hybrid Music System with which to make comparisons.

If you already own a Music 5000, then the Music 2000 will greatly expand your sonic horizons. If you've ignored the Hybrid Music System because of its previous lack of MIDI, you can afford to ignore it no longer. And if you're looking for a computer-based music system, now you know where to look. If your BBC micro's been gathering dust in the cupboard-under-the-stairs, dig it out!

Price Music 2000 £161 inc VAT.

Contact Hybrid Technology Limited, (Contact Details).