They are all (except for a single minuet) 'long variation sets'; sets of four or more strains, based on the same underlying harmonic pattern as the first, (typically only 2 chords), and all variations ending in a common melodic 'tag'. The tags of different tunes are clearly recognisable, and a feature of the harmonic scheme is how the underlying chords fit with the drones, and the rhythm of the resulting concord and dissonance. As an example, in "Gingling Geordie", typically for smallpipe tunes, the underlying chords are the tonic, A major, and supertonic, B minor – the latter is dissonant against drones sounding in A, and here each strain reaches this chord at its midpoint.