I want to talk a bit about the mesmerising quality of the second single from Radiohead's new album. It's to some extent rhythmic, melodic and textural, but mainly harmonic; and is so in a really fascinating and fresh way.The harmonic structure is basically really simple. It's in A minor with a little modulation to D minor in the second version of the progression (which is not played every time). The chords are basically triadic - although importantly not quite.I'm not sure how to describe all of them; for what it's worth, if we think of them in a jazz way (which isn't even helpful insofar as this way of describing them isn't temporal enough, doesn't display the voice-leading enough), I think it's Asus4 - F6(sus2) - C(sus2)/E - Dm9/F and then Asus4 - F6(sus2) - C(sus2)/E - D7(add11) - G7(add11) with alterations. But these names are really complicated (and probably ungrammatical) and distort how much the chords are really simple, all just triads/6s/maj7s with small modifications that have wonderful effects on the gravity of the harmony. This is what I want to talk about.So look at the first progression, the Asus4 to F6(sus2) or C(sus2)(sus4)/F. The d'' in the A wants to resolve, though at this point it's ambiguous between whether it wants to resolve to an A major or A minor. And resolve it does, to the C natural of A minor (but we still don't know what key we're in as we've had no B) - but as it does so the rest of the notes move down too, the treble notes down a step and the bass down a major third - so now we have this weird slightly polytonal thing going on, wherein the treble notes spell out the original chord again except down a step, suggesting a repeating pattern of resolutions to new dissonances (which is standard enough, in classical music anyway), whilst the bass unsettles this by descending 'too far.' In any case, though, a new 'suspension' is created: it could resolve in a number of ways, but one way is, if you read it as the C(sus2)(sus4)/F, by resolving down to a C/E. And the bass F does indeed resolve to an E; but the treble notes don't move, so now we have another sus chord, a C(sus2)/E, another lovely but unstable chord, which again wants to resolve in ways in which itresolve, but again only as the resolution is scuppered by movements in the other parts. (And wedon't know what key we're in! - is this fourth chord unresolved because it's leading back to the tonic A minor, or is it itself a tonic with a dissonance to be resolved within the chord? Going back to the Asus4 is I think enough to eventually establish the key of A minor, though.)It goes on in this manner: every chord is and resolves into an almost but not quite perfect and consonant chord (triad, 6, maj7).So what? Well the title: the harmony is floating, suspended, defying gravity, but without either denying or ignoring gravity. It's tenderly floating, kissing the ground. It feels to me just like daydreaming - neither asleep nor awake, between places. It's virtuosic writing: I can imagine writing very dissonant music or very tonal music, but not a piece that so perfectly catches and sustains this shimmering distance to consonance.We hear it in the B section too, but in a different way.Here we switch to the tonic major, sort of. But take just the first chord. Is this an A major with the changing tones of d''-f#''? Or a D major with a c#''and then e''-c#'' changing tones? Or does the harmony flitter between the two chords? And what key are we in here? We're surely at least in A or D major - but then we move down to an F major chord (unless it's a D minor - we have again the ambiguity of the previous chord(s)). All the intervals are consonant and natural, but yet the music never settles into a key or even a chord. It's so soft and tender.There's more, too: the 3/4 6/8 ambiguity (crotchets in the treble, dotted crotchets in the bass) is just unstable between two very stable time signatures, is itself almost but not quite stable. Yorke's vocal line hovers around the 3rds and 5ths of the chords, ensuring the harmonic ambiguity, and melodically has only a hint of movement. Rising up at the start of a phrase, before slowly falling again - then rising up again, just a bit higher, before slowly descending again. Texturally too, we have these wonderful Radiohead clouds of soft sustained chords and bright-but-soft metallic chimes. But the harmony is what really gets my gut.