Is this the most perfect Christmas song ever? A scientist in Boston says he's engineered the perfect Christmas song, by studying what lyrics, tempo, vocals, and musical key you need to make a hit. He found it was important to use words like Santa, snow, home, peace, and love in the lyrics...but especially the word Christmas itself. The song needed to be in a major key, have an average tempo of 115 beats per minute, and feature plenty of sleigh bells. Check out 'Love's Not Just For Christmas'.