In an article about the thirtieth birthday celebrations at Redhill (This Old Cat) I suggested that Joseph Haydn might properly 'be held responsible' for Matthew Fisher's Grand Finale.
The 'borrowed' music I had in mind was the Minuet from Piano Sonata No 26 in A major, which Haydn wrote in 1773. It is a quaint little novelty whose full title, Menuetto al Rovescio, reveals its secret: the first ten bars ('measures') are exactly reversed to form the second ten, while the following Trio employs the same reversing device with its first twelve bars (a more conventional length for a musical phrase of the period).
It's not a difficult piece to play from a modern edition, but in Haydn's day the mirror-image bars were left blank, so the pianist could put in the reversed music 'on the hoof', which is a great deal more demanding. It has to be said that it's a pretty thin piano piece, no more appealing to listen to than its contrived method of composition would lead one to expect.
In fact Fisher's piece derives very little from Haydn's, as following excerpts make clear. To facilitate comparison, Grand Finale's opening is here transposed up a fifth into Haydn's key of A major: the notes with red stems constitute the only shared material.
It can be seen that the harmonic scheme of the first four bars is common to both pieces, though Fisher uses a passing IIi chord on the last beat of his first bar; that the bass line in bars two, three and four is identical in contour, if not in range; and that the music for both hands could scarcely be more similar in bars three and four.
From bar five, however, the pieces diverge. Unconstrained by Haydn's 'looking-glass' formula, Fisher takes a far more interesting course: his piece, which comes in sixteen-bar phrases, is coloured by resolving suspensions; it then modulates stirringly from an original D major into A major for its second, counterpoint-embellished, statement. The guitar section, which in structural terms corresponds to the Trio, rotates a chord-sequence derived from earlier in the In Held suite: D (once minor, thereafter major), A minor, B major and E minor: This escapes from the final D major into a transitional G major chord, which heralds the return of the Minuet theme, this time in a triumphant C major.
To set the record straight, it would be fair to say that all Procol Harum have borrowed from Menuetto al Rovescio is its three-four time-signature, and elements of its first four bars. And, to this pair of ears, Grand Finale turned out a lot more interesting than its ancestor, both harmonically and melodically.
In Held 'Twas in I: read a full account of the Brooker elements, the Fisher elements and the Trower element.