I don’t get invited to many parties these days, but when I did, I would occasionally be asked the old standby question “what kind of music do you like?” Struggling for an answer beyond the glib – and in any case untrue – “I like all kinds,” I would reel off a grab-bag of genres including guitar rock, alternative rock, folk rock, free jazz and even (depending on how confident I was feeling) industrial. But the genre I felt most comfortable expressing enthusiasm for was progressive rock, having developed a grudging respect for my brother’s Genesis albums in my early teens, followed by my own belated discoveries of Pink Floyd, King Crimson and Van der Graaf Generator (in that order).