Hello fellow creators of vibrations and melodies. I'm a bigtime newbie and i use acid 5, FL5 and native instruments absynth 3. Now sometimes friends send me little songs they have done on guitar and i want to add stuff to them, such as sequenced drums and synth melodies. But obviously since they made the song first ( lets just say its acoustic with vocals) they made it at their own unknown tempo. How can i figure out a way to get the right tempo for the other guys song so i can toss in some drums and other stuff? I've been trying to figure this out for months. Like i'm not sure how remixing is really done but you have to figure out all your tempo problems while doing that right? i'm confused.