Do Re Mi comes from a motet by Guido d'Arezzo who started each phrase on a consecutive note of the major scale starting with "C". Actually, it was Ut,Re,Mi, and Ut is still used for the so-called 'fixed Do'. 'Do' came in later to represent a major scale where the tonic (main tonal center) could start on any note.

Sometimes nonsense syllables are used to create some sort of word game or tongue-twister as in the chorus of Jenny Jenkins or many versions of Froggie Went A-Courting (such as the "King-Kong-Kitchie" variants)