When the MIDI specification was being drawn up it was generally agreed that one of the primary requirements was that of cheap implementation. Hence it is possible to include the magic DIN sockets on even relatively inexpensive, non-professional instruments without adding a huge percentage price increase.

Thus, although there are currently few MIDI auto-play keyboards about, we will probably be seeing more and more of them in the future and it will probably become less of a stigma for a 'serious' musician to be seen using one as a song writing tool; indeed, even certain members of Ultravox have publicly displayed their keen involvement with the Yamaha PS-6100 for just that purpose.

As the name suggests, the auto-play facility offers the less musically fluent songwriter various levels of automatic operation. In a musical arrangement that might include drums, bass, orchestra and melody line, the human operator can choose to take full or partial responsibility for the performance of nothing, everything or any compromise twixt the two extremes. In most cases the overriding competence of the instrument's internal computer will fill in the gaps, and possibly even adjust to compensate for the imperfections of its struggling human accomplice. Thus with only two fingers the non-dextrous ideas person can put together the rough form of how a song might sound before involving the rest of the band or session players, etc.

The instruments mentioned here are the few top of the range models that might be considered as genuinely useful writing tools, although it is obviously not an exclusive list.

CASIO CT-600

The CT-6000 is doubly unique within the Casio stable because not only is it their only instrument to have a full-size, velocity and pressure sensitive keyboard, but it also stands alone in its inclusion of MIDE It has all the standard auto-play facilities plus what they term 'Super Accompaniment' which takes its cues from your melody line to add an assumed harmony which sometimes works and sometimes doesn't. The sounds are quite good, though generally not up to PCM standards.

SIEL MK-900

This is almost a clever little instrument but it's sadly let down by the quality of its voices — a serious deficiency for any vaguely musical user. Its cleverness comes to the fore in its 'double sound generation' facility whereby two sounds can be layered atop each other to create a superior hybrid. Alternatively, the keyboard can be split at any one of four fixed points with one sound either side. The drum sounds are particularly weak, but there is the saving grace of being able to programme your own limited rhythm. There is something new lurking in the auto-play department in the form of the 'Help' mode which is more or less like a 'Two-finger-chord' facility as opposed to the standard 'One-finger-chord'. Here playing the notes E and D in the left hand will result in an E7; if you actually wanted a D9... you're just too jazz.

YAMAHA PS-6100

The prince of auto-plays, the PS-6100 really can be looked upon as a real 'writing machine' without too much sniggering at the back. Although the voices are FM generated only the solo (mono) voices stand out as being notably excellent within the option of after-touch producing a fixed result such as added brightness or vibrato, etc. It seems that with the better quality sounds come more musical auto-play accompaniments and you genuinely get an idea of how a song might sound very quickly without having to record to tape. The drum sounds are PCM and also very impressive, and you also have a spare memory location into which you can write your own short pattern with a full array of drums and percussion instruments. If you want to buy an auto-play instrument, this one is undoubtedly the best on the market.