you can find songs that have been turned into midi's(but without singing), and use programs like 'cubase' to play them. cubase is the only one ive had, but im sure there are plenty others. it pulls all the instruments apart and you can select which it plays etc. and you can create your own tracks off tab/score for each instrument, and i could hook up my guitar and input to my pc and it would record the note down etc into midi. i could also get backing tracks of drumming for guitar playing with this program
however this program was expensive(cracked copy for me lol) and my sound card is a piece of ****...
i also have cooledit for just recording music, not that great, but beats windows sound recorder by heaps.
apart from all this, as said before finding a program and going and editing the drums out-though this would distort everything else