Composer Howard Goodall spends this episode on melody: why a handful of shapes turn up in tunes from every culture and every era, and whether that is coincidence or something built into how ears and brains process sound. He traces a direct musical line between Tudor England's choral writing and the blues of the Mississippi Delta, then pulls examples from Gustav Mahler, Paul Simon, Shaker hymns, Bulgarian folk songs, and Broadway showstoppers to show the same handful of intervals and patterns recurring across centuries and continents. Goodall plays and sings these fragments himself at the piano, breaking them down note by note to demonstrate why certain melodic moves land as satisfying and others don't, and asking whether a good tune can ever really be written by chance. The result is a working catalog of the tricks composers keep reaching for, drawn from classical, folk, and popular music alike, rather than a history of any single tradition. Made for Channel 4, part of Goodall's series on the mechanics of music.