There are, however, constants in Ligeti's musical imagination. One of the most important is the idea of the absurd. Ligeti's world of imagination was simultaneously an asylum, a place of refuge, and a place to process the horror of the 20th century's great geo-political nightmares through which he lived. As a child, he invented a self-sufficient world of his creation that he called Kylwiria; as an adult, he was a lover of Lewis Carroll (he wanted to write an opera based on Alice in Wonderland) and the surreal linguistic games and imagery of Hungarian poet Sándor Weöres. One of his very last pieces was Síppal, dobbal, nádihegedüvel, "With Pipes, Drums, Fiddles", a setting of Weöres's poems for percussion quartet and mezzo-soprano. They are, typically for Ligeti, on a tiny scale, and they make sounds like nothing else: each of the seven songs is simultaneously redolent of folk music and of modernist complexity, of childish immediacy and decidedly adult sophistication. Yet this music is absolutely, definitively new, and each number conjures its own little-but-large world of absurdist expression and resonance. They are also, I think, strangely melancholic. The Sippal songs have that quality that all the best absurdist poetry does of making you confront big ideas through lightness of touch, humour, and sleight of hand.