I haven't done too much recently, but with some experimenting I've found a way to get the length in seconds out of MML! This also considers loops and will tell you if it is infinite. I proved this further by making the program stop the song after it theoretically should be done - and it doesn't stop early or late! It also factors in tempo. This should be useful for BitByte MML!

Here's using two-digit beat values. Had to check the last bit twice, it was that fast!