Rick Wright confirms the new harmony with his opening piano chord. But there are soon plenty of further surprises in the pipeline as Wright’s introduction creates a sublime diversion from our main harmonic path with a ‘round the houses’ series of secondary dominants. Carrying the ear to somewhere completely new and alien. And yet, this is not wholly unrelated to the whole design...

Note how there are realisations of new, transposed II-V-I progressions as miniature motifs of the big, main one (yet to be completed, of course!) during Wright’s piano introduction. First of all, G minor -  C7 - F. Secondly, C minor  - F - B flat. Both are good examples of how the II-V-I progression smoothly transports the listener from one musical corner to the next. Also, both exemplify Pink Floyd’s fondness for the progression itself on this album.

Other than that, note that the repeated G minor to C7 sequence which takes up most of “Great Gig In The Sky” and serves as a platform for the main event - Clare Torry’s truly remarkable vocal solo - is a transposition of another prominent two-chord progression heard before on the album…namely, the repeated E minor to A7 sequence which takes up most of the song, “Breathe”. Note also that, whereas that two-chord sequence in “Breathe” isn’t yet followed by its third chord to complete a II-V-I progression (yet!), the transposition of that sequence as used in “Great Gig In The Sky”, is ie. Gminor - C7 - F. This is a hint of what is to come surely.

Interesting to note further that, despite featuring Gminor  - C7 - F somewhere as a II-V-I progression, “Great Gig In The Sky” ultimately ends on G minor to bring the song’s recurring two chord oscillation to rest and Side One of the album to a close. This is a transposition of what happens at the end of “Breathe” where, after so many repeats of E minor to A7, matters comes to rest on E minor.

So much recycling going on here… “Breathe” and“Great Gig In The Sky” may seem like two very different songs but harmonically there is so much in the latter that is recycled from the former (albeit in transposed form) which again helps to form connections and cross-references between distant points on Dark Side Of The Moon. As well as that, there is no doubt about how effectively this recycling pays off in the hands of Pink Floyd. So much drama comes from the later visits as here in “Great Gig In The Sky”.