ATARI NOTES

Fractal Music Composer

Published in SOS July 2000
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Technique : Computers

Derek Johnson finds that a picture plays a thousand notes, with Fractal Music Composer.

If algorithmic composition is your bag, the Atari is the computer for you. Following coverage of algorithmic classic M in my May 2000 column, this issue I'm having a quick look at another alternative composition tool. Enter the 1992-vintage Fractal Music Composer, written by Electric Light Orchestra cellist Hugh McDowell and reviewed back in SOS February '92 (Note that FMC is no relation to Datamusic's Fractal Music by Chris Sampson, covered in these pages in June '92 and November '97.)

The most recent version of FMC, v2, costs a rather affordable £35 plus postage (£2 EC, £5 rest of the world: postal orders, money orders or cheques, in sterling, payable to Hugh McDowell). It offers what the author describes as a more "controllable and useful" algorithmic composition aid than some similar software. The algorithms at the heart of FMC are derived from the fractal mathematics that generate, graphically, the familiar Mandelbrot and Julia sets; these algorithms create music based on the interaction between a collection of user-definable note and rhythm parameters and coordinates on the plots.

FMC comes as a two-disk set (one working disk, one key disk), and has three operating modes: a Mandelbrot zoom program, the fractal music composer itself, and a MIDI file player/converter. The first lets you zoom into the classic Mandelbrot plot, save the result and use the zooms as the basis for music generation. Be warned that plot redrawing once you've zoomed in can be very slow, especially on an unaccelerated basic ST with 288 iterations chosen. It takes half an hour or so with 72 iterations.

From FMC's main Composer screen the user controls how the program generates its music; up to eight patches of parameter settings can be defined and saved to disk. Six tracks are available, each equipped with a MIDI channel, lowest/highest note values defining the permitted note range, and a parameter for setting how a given track treats repeated notes -- they can be left as they are, or can be tied or muted (creating a rest). Whole tracks can be muted, too. From this screen you can also load fractal plots, choose Mandelbrot or Julia sets, set up MIDI sync generation (the software can't actually sync to incoming MIDI clock), and organise MIDI file export.

It's Only Words...     In the mid '90s Mark S Baines wrote a useful book called The Atari A to Z: A Dictionary Of Modern Computer Terms For The Atari Enthusiast. The book itself is out of print, but an ASCII text version is now available as shareware, downloadable from Mark's Linnhe Computing web site. Non-hard-drive users be warned: the uncompressed text is over 900K, and will not fit on one double-density floppy! The book itself is comprehensive, and aims to cover everything to do with the Atari family. There's detailed information for all levels of Atari ST, STE, TT or Falcon, from simple definitions for the uninitiated to technical data for the experienced. You'd be hard-pressed to duplicate its 2,239 entries, 101 tables and 128,000 words in almost any reasonable collection of Atari-specific books, and you certainly wouldn't be able to do it for less than the A to Z's £5 registration fee. www.stsd.demon.co.uk/linnhe.html

The Rhythm Map button takes you to the Rhythm Editor, where the number of notes per track, the length of each note and how they repeat is determined. The Tonality Map button opens the Tonality Editor, which lets you influence the note pitches generated by the program: a variety of scale types is provided, and by manipulating octave ranges and transposition you can dictate broadly what sort of 'tonality' a performance will have without knowing exactly which notes will happen when. You can even create your own scales. The last significant button is Set Coordinates. With this you decide which plot coordinates in the main fractal diagram each track will use. Two coordinates -- one each for pitch and note length -- are chosen for each track. The manual recommends choosing busy or chaotic areas in the plot, since these produce the most sonic variety. There's no way to reliably predict results here: just pick the bits of the picture that look most interesting!

Once you've made these choices, press the Compose button in the main window. Let the program run, and, if you hear something you'd like to keep, just stop FMC and press Replay to listen to exactly the same performance again (pressing Compose always creates a new performance). The Save MIDI File button will store the performance in memory to a MIDI file, making it easy to export FMC results to a MIDI sequencer for further manipulation.

Depending on what parameters you've set (and even if you've just ploughed in and changed parameters at random), FMC's output can be very melodious. It's possible to restrain note ranges and create scales such that clangorous and dissonant results are produced, but on the whole it excels at generating hypnotic, melodic music. When you get the hang of the Rhythm Editor you can even cause the program to combine busy, Terry Riley-like patterns with real tunes of a more flowing nature. Start with the 'instant gratification' section of the manual and tweak from there. One nifty feature I haven't mentioned is that if you work with the Julia set option the program actually draws six Julia set patterns, one for each track, as it composes.

If algorithmic music generation appeals to you, I can heartily recommend the facilities offered by Fractal Music Composer; it's a stable, comprehensible program that produces very interesting results and, at £35, is a long way from expensive. You can even try it out first for nothing: a demo can be downloaded from Tim's Atari MIDI World (sites.netscape.net/ timconrardy/index.htm).

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