Sorry for the new thread but I couldn't find all the answers I need - I did look.
I'm using beat counting software to mix dance music and I need a formula whereby I can determine what Beats Per Minute percentage value to enter to make two songs of differing speeds match.
For example, I have a song which is 140.8 BPM and another which is 143 BPM but of course when I add the songs to the mix they are both presented at 100% of their BPM and if played together sound like a pair of boots in a tumble dryer; I need to know what percentage to play the second song at so that it will match the first. In the above case, the song which is 140.8 needs to be played at 101.36% BPM. How do I know this? Because I matched it manually through trial and error (and having a DJ's ear) - its a slow, painful process which can hopefully be rendered unneccessary by a clever mathematician with a formula.
I suspect that creating this formula is fairly straightforward for one who knows their numbers, but alas I must admit it's beyond my meagre capabilities.