Folks,

I think that using backing tracks is fine in a performance (be it MP3s or MIDI files or auto-accompaniment styles) as long as you use it to enhance your own performance, and do not mislead the audience. We all use technology because it is a more efficient, affordable, and for some of us the only way to have accompaniment of any reasonable quality.

Once I met a performer in a hotel I stayed at - he was playing the grand piano in the lounge, accompaied by the mini-disk player through a Roland KB500 amp. Even though his performance amounted to an instrumental karaoke, he was a wonderful keyboard player, and the recorded backing tracks were primarily emphasizing his own musical skills. I think this is perfectly acceptable. On the other hand, I had been to a restaurant, which advertized a live band - the band was indeed there, but during at least a couple of songs I had caught them standing there only pretending to play, with the music coming from the record - that is real cheating in my book. I would have been fine with them playing the records if they had played them during the break, or at least had not pretended to be playing themselves.

Back to the original topic of this thread - I think each one has to be the judge of his/hers audience. While I may be accustomed to hearing a recording of a song with the big band background, someone performing the same song with a smaller style (e.g. the one emulating a 3-4 piece combo) will probably sound more original. I don't believe one has to sound exactly like the record - if the client wanted that, it would be cheaper for them to play a record than to hire me. On the other hand, I don't want to butcher the song in the name of originality either.

To me personally, playing along with the arranger styles allows to vary and adjust the performance to the needs of the situation - the type of the venue, the mood of the audience, etc., which is why I don't use MIDIs or MP3 files. Besides, my typical audiences usually include a couple of skeptics, who say that I am not actually playing, and my music is instead recorded - having a computer with me would only further their suspicions. However, if you feel you can use a laptop (or an Ipod), so much the better.

That's my $0.02

Regards