In ritual work, most medieval books would seem to have you work in silence and by candlelight. But what about magick in this 21st century? If you don’t subscribe to the “electronics are bad during rituals” philosophy, you may have had some suitable background music on during a ritual; you may have even used suitably atmospheric electric lights (“LED candle” lighting is particularly good for this).
But non-distracting music is needed for a ritual: in my mind, it needs to be a drone without too much variation, sans vocals and with a mood suitable to the ritual. In these iPodian days, it’s trivial to set it to repeat until the ritual is complete.
Here’s a first suggestion: Lustmord, Where the Black Stars Hang. Just because it’s a ritual I don’t think something that sounds like horror movie music would really work (but if that floats your boat: do it!) and this Lustmord CD is a dark yet not gloomy wash of sound from deep space. The first song is even called Sol Om On (Solomon? Music for Grimoires?). Perfect for the purpose.
If you’re not familiar with Lustmord it might sound like a German black metal group, but really he (it’s one guy) is a master of the dark ambient genre.