of fifths, though a ladder of thirds differs in being composed of thirds, major or minor, and may or may not circle back to its starting note and thus may or may not be an interval cycle. Triadic chords may be considered as part of a ladder of thirds. It is a modal frame found in Blues and British folk music. Though a pentatonic scale is often analyzed as a portion of the circle of fifths, the blues scale and melodies in that scale come, "into being through piling up thirds below and/or above a tonic or central note." They are "commonplace in post-rock 'n' roll popular music – and also appear in earlier tunes". Examples include The Beatles' "A Hard Day's Night", Buddy Holly's "Peggy Sue" and The Who's "My Generation", Ben Harney's "You've Been A Good Old Wagon" (1895) and Ben Bernie et al.'s "Sweet Georgia Brown" (1925). Example The modal frame of The Beatles' "A Hard Day's Night" features a ladder of thirds axially centered on G with a ceiling note of B and floor note of E[] (the low C being a passing tone): According to Middleton, the song, "at first glance major-key-with-modal-touches", reveals through its "Line of Latent Mode" "a deep kinship with typical blues melodic structures: it is centred on three of the notes of the minor-pentatonic mode [on C: C, E-flat, F, G, B-flat] (E-G-B), with the contradictory major seventh (B) set against that. Moreover, the shape assumed by these notes – the modal frame – as well as the abstract scale they represent, is revealed, too; and this – an initial, repeated circling round the dominant (G), with an excursion to its minor third (B), 'answered' by a fall to the 'symmetrical' minor third of the tonic (E) – is a common pattern in blues." See also Melodic motion Tune-family References Musical techniques Melody