I just use the tap tempo button on the MPC, but the main thing is to make sure your sample loops when its being chopped, then I set the tempo, then turn it a little higher to set the swing, a surprise might be is that when you listen to some of you fav songs the loops don't always loop up. the lyrics and other insturmenation make them fit. Also when you sample records the people then were playing live so the tempos will vary.