Passport's MIDI hardware and software packages have just about tied up the US market - designed for the popular Apple and CBM 64 computers, Passport products have become so popular that other manufacturers are now bringing out products designed to be compatible.

The two packages we looked at are a four-channel real-time MIDI recording package for the Apple or CBM 64, MIDI/4, and the powerful music transcription package Polywriter for the Apple II or IIE.

POLYWRITER

Of the two packages, Polywriter is undoubtedly the more interesting. Music transcription, allowing untrained synthesists to produce written music, has been the aim of many software packages - but until now, none of them have made it.

Polywriter gets the fine balance between under-resolution and over-resolution just right - it neither unnecessarily records the tiniest variations in technique and timing, or inaccurately merges notes which are actually fingered separately.

Each package needs an interface to run it - the Apple MIDI interface is a small printed circuit board with three flying DIN leads for MIDI In, MIDI Out and MIDI Drum sync which fits into one of the Apple's many rear-panel slots.

Polywriter's main screen allows you to create a piece, Edit it before printing, Save it on disk or quit and format a new disk. If we go on to Create we're faced with a variety of option's for Filename (simply the name of your song), Printed Form (of which more later), Key, Meter, Tempo, Density (of notes which can be printed, maximum 2,512 per page), and Resolution ("error correct" on notes recorded). Default values are provided, and the Apple provides a metronome beat to play against if you're not using a drum machine.

Having displayed the music you've played on the MIDI synth, Polywriter can then be used to edit the score to polish your performance before printout. The basic form of notation is Piano, which puts your music onto a bass and a treble clef. Other options are Treble only, Bass only, Choral, Treble with Piano, Bass with Piano, Choral with Piano and Full Orchestral. Of course, you'll need an Epson or similar compatible dot-matrix printer with interface.

Separate files have to be opened to record pieces in different tempo, but the pieces can then be combined for print-out. Editing a score is simple, just place the screen cursor over the offending note, and play the music keyboard to replace it. It's equally simple to add lyrics.

It's terribly difficult to perform a complete test on a package capable of reproducing a twenty-piece orchestral score spread over dozens of files on half-a-dozen disks. However, the small handbook is well written and appears to cover just about everything you'll come up against. If your budget stretches to a 64K Apple II, disk drive, monitor, interface cards and printer, Polywriter is the package to get - and a CBM 64 version is forthcoming.

MIDI/4

MIDI/4 is a much more modest proposition, designed for the Apple or CBM 64. The 64 MIDI interface is a much neater affair than the Apple's consisting of a cartridge which plugs into the 64's port, with the usual three trailing leads.

MIDI/4 allows you to record four real-time polyphonic MIDI tracks, with full touch and modulation information, then merge them into new tracks so that in effect the number of overdubs is practically unlimited - within the limitation of the CBM 64's approximately 6000-note memory.

The program's main screen displays the status (record, play, off) of the four tracks; the MIDI channel assigned; the sound preset of the instrument used; and if you wish, the name and sound of each instrument.

Information common to all tracks include the tempo, drum machine sync rate, number of intro clicks on the metronome, transposition (if any) used on playback, looping on/off or touch response on/off. This last feature uses up lots of memory, so it should only be used when necessary.

You move around the menu with the 64's function keys, and start recording by pressing the space bar. Having finished your performance, which is accompanied by both an audible and visual prompt, just hit the space bar again to stop, place that track into PLAY mode and RECORD the next.

The system has a few major disadvantages. Firstly, it's totally real-time; there's not time-correction facility and no way to "edit" a recorded track other than punching-in to a silent spot and redoing it. For that matter, there's no visual display of the music recorded. There's also no facility for defining "loops" within a composition; only the master track, track one, which has to be the longest of the tracks, can be made to loop. The method used for defining loops is also pretty naff, requiring the insertion of "false notes" to define end points.

Erase, Punch-In and Mix are fairly straightforward, though you can't Un-Mix tracks so it's a good idea to keep working copies on disk.

MIDI/4 seems to have many disadvantages; totally real-time, no error correction, no editing, no visual display, limited number of tracks without mixing. However, it's simple to use, and for a limited MIDI system - especially one with only one synth and drum machine - it serves its function perfectly well.

Distributed by Rittor Music, (Contact Details).