I'd be happy to do this for you in a timely manner if you're interested. I'll need to know the song you are looking to have the music removed from, and I'll tell you if it's something I can do or not. I've been working as a mix-engineer for 7 years, so I know my way around audio. Just a warning though, you wont be able to get an acapella extracted from any original song without artifacts, and in some cases, it might actually be impossible unless you purchase mix stems for that song. A good example of this would be Ellie Goulding's song "Lights" where the vocals from the verses can be extracted, but the vocals cut out in the chorus, and this is due to audio phasing/panning isolation problems, however, the original stems are out there somewhere (and I know because I've listened to them personally).
If you're interested to see what I can offer you, send me the name of the song in a message and I will tell you if it's something I can do for you.