Singers occasionally need a recording of accompaniments, either to sing along to for practice or, the odd time, for performance in a venue with no piano or keyboard (busking is an obvious example). In the former case I can easily record something functional for you, but for the latter, when you might want to be sure that rubato moments and cadential points are right for your own performance, we can get a nicely tailored result if you come to me and sing through the songs/arias in question while I accompany you on my Roland keyboard. At the same time, I record the line output of the keyboard, which means the recording only features the accompaniment, not your voice at all. I then copy the recordings to my computer, edit them (if needed) and email them to you or make a CD.
The downside of this is that the accompaniment is only a digital instrument but, quite frankly, by the time it's been played out over a PA system (or worse) it won't sound too bad at all. The upside is that it will fit your singing perfectly - at least until you completely rethink your interpretation!
Cost: for simple accompaniment recordings (i.e. where I just estimate a speed, or you give me a metronome mark or other basic guidance) I price this the same as learning recordings, £25 per hour of finished recording (slightly more per hour according to a sliding scale below 24 minutes, down to a minimum of £5 per order). For custom accompaniments as above, priced by negotiation but essentially my hourly rate, £20, for as long as the job seems likely to take.