How to delete the uncommon sounds in 2 mp3 files

Question

Hi
Is it possible to do this with 2 mp3 files?
http://funkyimg.com/u2/438/320/Untitled-1.png
I want to leave the common sounds intact
and delete the sounds that are different :|
for example
2 songs with the same melody but different lyrics
Sorry for my english
And any help would be apreciated

Answer 1

Yes...but it's difficult, and you probably won't get a clean result - it'll have all sorts of digital mung - doubly so for mp3 files, where information is thrown away for the sake of compression during encoding. I assume you have 2 versions of the same famous song, remixed by different artists? Here's how:
load the two songs, which we'll call VersionA and VersionB.
Go into multitrack view and line them up on adjacent tracks. The start and end should match perfectly if the music is really the same.
Select both tracks. Menu: Edit|bounce to new track. This will give you something that sounds like the two mixed together, ie both sets of lyrics in 1 track with the background music louder than before. Call it VersionC.
Highlight on VersionB and go into Edit mode.
Menu: Effects|Invert.The waveform will appear to flip upside down.
Back to multitrack. Select VersionA and VersionB. Menu: Edit|Bounce to new track. This will sound like the lyrics from both tracks minus most of the music. Call the result VersionD.
Repeat steps 4 & 5, but on VersionD.
Back to multitrack. Select VersionC and VersionD, then Menu: Edit|Bounce to new track. This will cancel out most of the lyrics but leave most of the music.
Unfortunately, it won't sound that great, and you'll probably still hear the lyrics with a sort of echo quality. There is nothing you can do about this. One thing to try, though, is to search the net for a version of the song with no music at all. For example, search 'Remix_artist The_Famous_Song acapella'.
If you're lucky, you might find a file of just the vocals for one of the remixes (an 'acapella' is a song with just vocals and no music, a lot of artists leak them). If you do find it, then start a new multitrack project, load the remix you already have, and then take the acapella track and move it around until it matches the vocals in the remix. You might need to cut it into several pieces if the timing is not the same, eg the first verse matches perfectly but then the chorus is out of sync. You will know it is right when you play back the song and it sounds perfect except that the lyrics are twice as loud (because you have an extra copy of just the vocal). If the acapella is a mono file, leave it panned to center.
Once you are in this situation, apply steps 4/5/6 to the vocal track - select the vocal, invert it in edit mode, return to multitrack then mix both together. Mixing the original with the inverted vocal will cancel out the vocal without affecting the background too much.