In my drums / keys / vocals duo we've been using homebrew / commercial midi files, and before that stuff I created on my Ensoniqs, since the late 80's. The first song I ever did was the "Pet Shop Boys" version of "Always on my Mind*, after all they are using the technology so why can't I?

All the files we use are remixed / adjusted to leave space for us to play. We have never tried to suggest that we are playing everything but equally we firmly believe we are adding to the sound and not just doing glorified karaoke.

The game changers were a number of party nights were we were doing alternating 30 minute spots with a very good DJ. We would start playing as he faded out, and we thought we were doing pretty good versions of the tunes and yet as soon as the sound changed we were faced with an empty dance floor. So we started to use backing tracks more and found that the fuller sound held the crowd on the floor. The next big changer was the PSR3000, with the on board smart media and the 'next song' ability we could chain these together without waiting for the floppy disc to catch up. No gaps, no chat, and no chance for the floor to clear whilst nothing happens.

Doing this does not detract from the fact that we are still picking songs as we go to best suit the mood of the crowd. To us this is one of the crucial skills of good entertainers (and indeed DJs) that separates the good from the so-so.