The title of his column and book "Metamagical Themas" is an anagram of Martin Gardner's previous column "Mathematical Games". It's clever wordplay turtles all the way down.
- Gödel, Escher, Bach: an Eternal Golden Braid (you have GEB/EGB, and I guarantee you he noticed those notes form a musical triad)
- Metamagical Themas (anagram of Mathematical Games)
- Le Ton beau de Marot (I don't have my copy at hand, but "ton beau" is surely a pun on "tombeau" meaning "tomb")
- The Mind's I (editor) (I = eye)
- That Mad Ache (translation of "La chamade" by Francoise Sagan; "mad ache" is an anagram of "chamade")
I'd find it a cleverer bit of wordplay if "le ton beau de ..." itself didn't feel clumsy. Surely it would always be "le beau ton de ..."?