Pedal Point

Hold one bass note. Move the harmony above it. The bass doesn't change — but the chords change anyway, and the ear assembles the sound into a kind of suspended tonality: everything sounds anchored to the bass note, even when the chords above formally belong to different roots.

Here the bass is the tonic of each key, held as whole notes through a ii-V-I progression above. The ii chord (Dm7 in C) over a C bass becomes Dm7/C — which the ear hears as a C6/9sus colour (D = 9, F = 4, A = 13; there's no 7th in it). The V voicing — the rootless G13 shape F-A-B-D — over C sounds as Cmaj13sus: F is the 4, A the 13, B the maj7, D the 9. Only the final I chord aligns bass and chord. The tension between bass and harmony is the whole point.