Q: I wrote a song as a lead sheet and want to know how long it is. It's 112 measures long, in 4/4, and 119 BPM. How can I gauge how long it is, without having an opportunity to record it. With Math?
A: 4/4 means 4 beats per bar, and it's 112 bars, so 112 x 4 = 448 beats in the whole song. at 119 beats per minute, ... 448 divided by 119 means 3.76 minutes. about 3 minutes and 3 quarters of a minute.  so that's 3 minutes and 45 seconds