I also attended the seminar prior to the lecture which was on the topic of ‘Music Design’. Of course, music and graphic design being my two biggest passions, it was very interesting.
I'm sure someone must have taken this idea and applied it to modern music. Punk rock would be good. In fact, I'd like to have a go at creating a punk rock family tree myself… but I don't know the genre that well.
EDIT: I forgot to, A) actually point out who designed/drew these family trees and B) where I found them. They were designed by Pete Frame, many of which can be viewed here. I also asked my dad about them and apparently he did in fact have a book with these in but it has long since gone to the charity shop – damn! Although he said he has a CD, History of Fairport Convention, that has one on the front cover.