I once worked with an Irish audio engineer, I don’t know if the fact he was Irish has a bearing on this but he had an interesting way of determining the length of pieces of music. He worked in a studio run by video production outfit and would be asked to music of a specific duration – quiet often 28 second for commercials. His solution was simple: the music was produced on a machine running at 15 i.p.s. (15 inches per second) therefore he deduced that a 28 seconds long piece of music would be 420 inches long i.e. 35 feet long. So he would take out his tape measure and measure off 35 feet, snip it with a razor blade and deliver it to the video producer.