With all the excitement that's been generated by Atari's 16-bit 520ST machine, it's difficult to remember that the thing's already been about for a year. The music software houses have been slow to respond to the challenge set by such a powerful but affordable machine, perhaps because Atari went through a spot of financial difficulty similar to Commodore's recently.

But Atari-ites had a field day in March with the world's first Atari User's show being held in London's Novotel. The three-day show was packet out, and saw the launch of two new machines — the Atari 1040ST, which as its name suggests has a MegaByte of memory (at less than a dollar per kilobyte for the first time); and the 520STM, which has its operating system on a built-in ROM chip (so you don't have to load it up at the start of every session) and an output for a conventional television set rather than an expensive monitor.

So what can the 520ST models offer? Because they're 16-bit (dealing with numbers up to 16 binary places long as opposed to eight on the Atari 800, Commodore 64, Amstrad and Spectrum computers) they're very fast in operation, with loading to and from disk being equally efficient.

Specialised colour chips and a graphics operating system called GEM ensure that the Atari's colour display can be highly spectacular, and operation from a mouse (a hand-held roller-and-switch combination) keeps things simple.

The Atari's Apple Macintosh-like mouse operation means that a well-written piece of music software will involve you in the minimum of typing. Unlike the Commodore Amiga, the 520 isn't multi-tasking, so you won't have the advantages of being able to load one piece of music while you're playing another, or play a piece of music while you're creating a live light show with the computer (the spectacular Llamasoft Colourspace package is highly recommended for such hippy applications).

But the 520 has one musical advantage, which is the inclusion of MIDI In and Out ports on its rear panel. This certainly saves spending between £30 and £130 on a MIDI interface, although in some ways it may be limiting since it denies you the possibility of having DIN sync, footswitch and other sockets.

A flood of professional music software is now on the way for the 520, with Steinberg's 24-channel version of their wonderful Commodore 64 Pro 16 Sequencer package being at the head of the race. Packages are also on their way from Mark Of The Unicorn, Hybrid Arts and other American companies, and we'll be looking at these as they become available.

Already on the market is The Music Studio from Activision at around £29.99. Again a translation from the Commodore 64, TMS has the advantages of the mouse and improved graphics on the Atari. Basically it's a compositional package for the Atari's built-in three-voice sound chip, which is much less powerful than that on the Commodore 64. The synthesiser page of TMS offers you a four-stage envelope, octave control, tone and noise on and off, and that's about it; a Test function plays a scale with your sound to check before it's named and filed to disk.

15 demo sounds are provided, and each sound is colour-coded. There are also 15 excellent demo tunes, from the classics to Country and Western. Assuming we're more interested in composing our own tunes, TMS gives two ways to do this; either using a method of colour-coded blobs of different lengths (the Paintbox page) or using conventional music notation.

You can enter notes or blobs with the mouse, having pulled down a menu of different possible note lengths, and convert instantly from one system to the other so that even the totally musically inexperienced can produce a neat and professional-looking score. Scores can be as complex as you like, with alternative menus pulling down to select ties and measure bars, triplets, accents and dots, different note lengths and different rest lengths. You can rapidly alternate between different sounds (for instance, having a constant bass and drum sound with a flute and guitar solo alternating over the top), but if you write more than three simultaneous notes, the computer won't be able to cope.

This is where the MIDI facilities come in, with a whole page devoted to assigning MIDI output channels to each sound, deciding which synth preset they will call up (from 1 to 80) and which octave they will play in. The demo tunes were written using the standard sound set of a Casio CZ-101 in Solo mode, so that four different independent monophonic voices will play in addition to the computer's three.

As you're composing with the Mouse, both the computer and synthesiser will sound the appropriate notes, and when you have a completed passage you can copy it, move it, transpose it, change the instruments used, and so on. Total capacity is 8,500 notes per song which is enough for more than 10 minutes of music using three voices. Of course, if you use several MIDI synthesisers (a Casio, a DX7 and a Juno for instance) you can use as many simultaneous notes as you like (up to a limit of 15), so the MIDI aspects of the package are quite powerful.

Disk loading is extremely rapid so live use is a possibility, but the software doesn't produce a MIDI clock so you'd have to write in MIDI drum machine parts as you would other notes.

The 520 looks like a good bet for the musician, and has helped Atari back to financial stability. Obviously all the usual accounts, database and other packages exist for the machine, so if you're thinking of investing for your studio, the 520 should be checked out. We'll be looking at more Atari-based packages as they come in.

On to another 16-bit machine, the IBM PC, which isn't as affordable as the Atari but which is used by many businesses in the UK. Luckily some of the better (cheaper) IBM copy machines, such as the Qubie, are virtually 100% compatible, so programs such as Roland's MPS (Music Processing System) run perfectly.

MPS is a powerful multi-channel MIDI polyphonic composition, editing and printing system which gives the user an unprecedented amount of control and flexibility. The Song mode gives a display of eight tracks (each of which can contain polyphonic MIDI information on all 16 channels) and there's a ninth Conductor track to hold tempo changes. 80 of the 32,000 bars available can be viewed at any one time, and bars with music recorded in them are shaded in for easy reference.

Note entry is in real time from a synth or mother keyboard, and performances can be quantised as desired. Phrases can be defined for copying, editing or independent storage to disk, and MIDI channels can be altered or offset from their original value. Phrases can be transposed and stripped of velocity or pitch bend information, and most operations are carried out using just the function and arrow buttons of the IBM.

The Score functions display music in bass and treble clefs and allow you to replace notes with the cursor and make the music score more comprehensive, without necessarily altering the MIDI information actually present. Once you're satisfied with a finished score you can go into the print mode and print up to 24 bars (four staves of six bars each) on each sheet.

MPS is a highly versatile MIDI composition system which will satisfy the demands of the most professional studio, having the ability to sync to SMPTE through an SBX-80 unit. But it is costly, needing the following equipment to work.

The computer must have a colour output card even if you use a black and white monitor, and a 640k computer will give you 65,500 notes capacity.

Roland have also launched the SJE, an IBM editing/library software package for the Super Jupiter module which comes with a large number of factory sounds and the ability to store sets of two sound banks to cartridge and one to the synth. Using the Quarterdeck DesqView package, MPS and SJE can be used simultaneously to create an enormously powerful system. It's also possible that IBM Emulator packages could allow cheaper computers such as the Atari to run MPS and SJE, although it's unclear how the control functions would work or how you'd load a package on a 5.25" disk into a machine with a 3.5" disk drive.

Next time, down to earth again with some budget computer goodies and a look at more Atari and synth editing software.

MPS and SJE are marketed for Roland UK by MusicCalc, (Contact Details).

Activision Software is available through all computer stores.