Elvis Presley, The Rolling Stones, David Bowie and The Sex Pistols may come and go, but rebellion remains a key part of the rock n' roll experience. However, that rebellion - the outgrowth of a youthful search for independence and identity - doesn't always take the same form.

I suppose, the natural outgrowth about writing about two friends, it becomes about their friendship, and the complexities of it, and the way personality plays off each other, and what they each like to do, separately and together.

I do quite like Gehry's Guggenheim. But where in Bilbao it's seen as an outgrowth of years of investment in urban design and engineering, in Britain it's seen as the catalyst for urban regeneration rather than the icing on the cake.

*Appendix usually means "small outgrowth from large intestine," but in this case it means "additional information accompanying main text." Or are those really the same things? Think carefully before you insult this book.