I just have two brief (but hopefully interesting) points to bring up about this Jethro Tull album.
1. Gerald Bostock was made up by Ian Anderson. A quote from the bonus interview on my copy of this album:
It was a concept album in the sense of, uh, beginning with the preposterous idea that it was written (lyrically anyway) by a twelve year old boy called Gerald Bostock, if memory serves, and, erm, even now people will say, "Wow, Gerald Bostock, must be now - he must be now - he must be getting into his thirties!" People still, believe it or not, seem to think he's a real character.
2. If you look at the front cover photo, you can see that the girl sitting in the chair (supposedly Gerald's fellow poet Julia Fealey) is subtly hiking up her skirt to reveal her knickers.