This sampler, given away free with the NME in 1973, isn’t in here because it’s rare but because of the beautiful sleeve. A mini replica of Emerson, Lake & Palmer‘s ‘Brain Salad Surgery’ album cover, complete with HR Giger paintings and fold out, die cut cover, that’s some promo budget being blown there.
The first track, the song ‘Brain Salad Surgery’, didn’t actually appear on the album of the same name but was first released on this flexi and later used as the B-side of the ‘Fanfare for the Common Man’ single. Fun fact: the title phrase is apparently a euphemism for fellatio.

What’s hard to find is a good condition copy without any folds or tears as the cover is just paper rather than card. As for the music, I’ve got to say, I’m more a fan of the sleeve than the music inside it even though it has it’s moments. Here’s some more info about the making of the cover from HR Giger’s website.