New Scientist on the three minute pop song: "Right back to Kylie in the 1980s, I have always looked at beats per minute as fundamental to a song. Anything too slow and you get a lethargic reaction. With Stock, Aitken and Waterman we were trying to make people feel uplifted and get their heartbeat moving. There is definitely a point somewhere around 120 bpm when it starts to get excited."