“5:15” is a song written by Townshend in 1973 for his band “The Who”. As Pete said:

His (referring to Jimmy, Quadrophenia’s main character) train journey down to Brighton, sandwiched between two city gents is notable for the rather absurd number of purple hearts he consumes in order to wile away the time. He goes through a not entirely pleasant series of ups and downs as he thinks about the gaudier side of life as a teenager that we see in newspapers like the News Of The World. ‘5:15’ was written in Oxford Street and Carnaby Street while I was killing time between appointments. I must try it again sometime, it seems to work!

David Bowie, who had Pete Townshend on his studio set to record some of the songs of Heathen album, decided to present his visual impression of the decay of the US with a little tribute to The Who’s song.