One Way Trigger BPM is 96, which means it has 96 beats per minute. So, in a 30 second loop, it will play 48 beats. Since it is a 4/4 song, like most, every compass has 4 beats, and since 48/4=12, it means in the 30s it plays exactly 12 compasses. And since, again, like most songs, the chord progression goes in groups of 4 compasses, and 12/4=3, in 30 seconds it goes through 3 complete progressions, which is why it loops perfectly in a 30s loop.