how to record to an instrumental

[illicit_records]

I just started recording some rap tracks and was wondering what's the easiest way or program I can use so I can record to the intrumental at the same time it's playing. So that I don't have to go back and add the acapella to the instrumental because this takes a lot of time to get the vocals in sync with the beat. also what program is recomended for doing this.

[Infamous Lab Rat]

what type of gear are you using?

[Genetix]

cool edit pro. is the best to use if all your'e doing is recoding over beats.