Francis Poulenc is one of those composers whose personality shows very clearly in his music. Some composers, you sense, enjoy the process of creating a pure compositional line swept clean of their personal feelings. We may know from reading their biographies that they were complicated people, but you wouldn’t know it from their music. Was Mozart sad when he wrote such-and-such a sad aria? Or could he just write in whatever spirit he wanted, regardless of his actual mood? Some composers had such a grip on the formal beauty and logic of their music that they were able to disappear behind it.

Not so with Poulenc, whose blend of sentiment, wit, charm, and casual flippancy was probably a good self-portrait. He had many sides to his personality; the Poulenc of the religious choral music or opera (Dialogues des Carmelites) can be extremely serious. In his piano music, however, perhaps because of the piano’s association with cabaret and popular music, he let himself be capricious and mercurial.

The three Novelettes are not really a set – no 1 was written in 1927, no 2 in 1928, and no 3 came over thirty years later in 1960. The first and third Novelettes are very similar in style despite being written so far apart. No 2 is a spiky ballet which recalls Cocteau and the cheeky dissonances of the French cabaret style.

Sometimes Poulenc sets out to create a hushed and lovely atmosphere, but then can’t resist cutting through it with a callous march theme or a banal little jig. Often, when he has immersed us in warm and luscious harmonies, he cancels them with acid chords which seem to say: ‘Think I was showing you my true feelings? Ha ha! Think again. This is all just a game to me.’

At the top of the third Novelette, he quotes a couple of bars from El Amor Brujo by his friend Manuel de Falla, and takes them as inspiration for his theme. De Falla’s theme is in a swaying 7/8 time. Poulenc’s tribute is in a simple 3/8. In other words, he takes a distinctively Spanish rhythm and irons it out, making it more ordinary.

Poulenc was full of these contradictions. ‘I hate rubato’, he said in 1954. ‘ Never prolong or shorten a note value.’ On the other hand, he wanted his music bathed in lots and lots of pedal: ‘People never use enough pedal’, he complained. These two instructions are not compatible. If you bathe everything in pedal, some note values will inevitably be prolonged.

He was also strict about tempo. Three times in the Novelettes he forbids slowing down: ‘Sans ralentir’. ‘Surtout sans ralentir’. ‘Absolument sans ralentir’. All very well, but these all occur in places where his music would naturally suggest a bit of gentle leeway. With such slightly perverse guidance we’re halfway to Erik Satie’s world of contradictory instructions – designed, perhaps, to poke fun at us for taking composers so seriously.

‘Put butter in the sauce!’ was Poulenc’s advice to pianists. But sauce is not a dish on its own. What is the sauce for?