Last night we went to a concert presented by the Cape Philharmonic Orchestra in Cape Town’s City Hall. It was a trial getting there owing to the residuum of the major traffic disruption that accompanies the opening of South Africa’s parliament. But after that we settled down for an evening of Romantic music – it was St Valentine’s day after all.

First on the bill was Cesar Franck’s Symphonic Variations with Yulianna Avdeeva as the pianist. F sharp minor is the key with a shift to F sharp major intermittently and a brilliant ending in the latter key. Since F sharp major is one of those complex keys with multiple sharps and because I am now ready for the effects of my new tonal perception, I was not surprised when the latter part of the work sounded as if the musicians were playing in G major, a semitone up. Gone was the pleasure of the black note feeling of F sharp major. From where we were seated, we could not see Avdeeva’s fingers. Perhaps my brain would have shifted my tonal perception back down a semitone if we had been able to see her fingers skating over the black notes in Franck’s skittish final variations.

Next on the bill was Chopin’s 2nd Piano Concerto, in F minor- Avdeeva allowing herself to perform two works in tandem! I was ready for the wonderful four flats, the full round gorgeous key of related A flat major to sound in the non-descript key of A major, one of my least favourite keys. Usually after the permutations and perturbations of the development section of sonata form (as in the Chopin 1st movement), the return of the main themes in the recapitulation is associated with the upward shift I have come to expect. Miraculously and gloriously this did not happen this time. And more wonderful to relate, neither did the A flat major slow movement shift. Its A flat minor (7 flats) restless middle section did go to A minor (no flats or sharps), but, again miraculously, the return of the beautiful main theme was solidly and beautifully in A flat major. The finale did not shift either, allowing the horn to call in F major, not F sharp major, to herald an exciting end to the concerto. Avdeeva was induced to give us an encore (she had played beautifully, a real treat). She chose Chopin’s Valse Brilliante in A flat, and in A flat it was!

So why these differing experiences? What was happening? It cannot be a pitch or frequency phenomenon as the orchestra did not re-tune to a lower pitch and piano certainly did not! It was not an act of will on my part. I cannot will keys not to change – I have tried.

This morning I put on a CD of the Chopin 2nd movement and before long I heard the sound of E dominant 7th which told me that A flat major had shifted up to A. So what was special about last night? Let’s give thanks to St Valentine and be content.