At the height of Beatlemania, when they realised the earning power of their songs, John Lennon and Paul McCartney would, according to the latter, sit down and say, "Let's write a swimming pool."
And when Sammy Cahn (1913-93), lyricist for scores of Broadway and Hollywood songs, was asked which came first, the words or the music, he always quipped, "The phone call".
Such pragmatism when it comes to money is perhaps to be expected in the world of the jobbing songwriter.
But who said, "My sole purpose is to make as much money as possible, for after good health it is the best thing to have"?
That was Mozart, and this apparent heresy in the rare air of the classical world is dropped casually in this insightful, funny and frequently provocative little book by Caddy, a senior lecturer in music history and theory at the University of Auckland School of Music.