Maybe it was the wrong word. What I mean is a song that, as a consequence of singing it, enables an emotion that you have to be expressed or one you don't want, to be got rid of. Of course, all singing/music-making does do that to a degree but there are particular songs that I sing that always make me feel better.

'Geronimo's Cadillac', is another one and 'The World Turned Upside Down'