Haha, nah it's cool. What you do is play the files, and place your mics up against your speakers. Obviously you need to sync it up with the song you're playing on the game. What I like to do, is pause the file just where I start to sing. Wait for the game to get to that point then press play on the file. If you time it correctly, and your speakers are loud enough it'll hit the harmonies for you. For the triple fabs, I have uploaded files which hit the orange and brown, so you will need to sing blue. Confusing! If you have any trouble with it, let me know.
I do still own it, but the harmonies cannot be completed online. I've uploaded the files required to complete the harmonies, so if you use them you will be able to get the achievements. Visit the "A Gift For You" thread in TB:RB forum, you will find the files there...Good luck.