program that can completely remove vocals or instruments?

Question

ive heard of audacity but all it does is mono-fy the song & it sounds terrible, I was hoping that there would be a guud program that could actually remove all of the vocals & not leave bits of the song with vocals, or the program can remove the beat & just make it an acapella, eithier way i need a program that can do both or just one of them- (but it has to be free) pls & thank you in advanced =)

Answer 1

http://www.ethanwiner.com/novocals.html
says
Sometimes a vocal can be removed almost completely, but just as often the results are disappointing. In most cases you'll be able to reduce the vocal level, but some audible remnant of the original performance will probably remain. Further, any process that changes the vocal track is sure to affect the other instruments as well.

http://www.acoustica.com/mixcraft/tutorial/how_to_remove_vocals_from_a_song.htm
says
It is very difficult to completely remove vocals from a song.

both seem to be selling software to do it. Mixcraft has a free trial download.

Answer 2

Vocaloid