One of the best bits in Eddie Murphy's Raw is a skit early on in which Murphy recounts being chastised on the telephone by Bill Cosby for using so much foul language doing stand-up. Afterwards Murphy calls Richard Pryor, "And Richard was like, 'Tell Bill Cosby to suck my dick!'" The way he gets, just perfectly the vocal mannerisms of Cosby, and especially Pryor, betrays hours spent studying their records as a child. The mimicry is all in the voice - he doesn't really get them physically. It's a little like what Simon Reynolds is talking about in The Guardian - a portrait of the artist as a consumer. A similar thing happens towards the end of Woody Allen's much-maligned homage to the Hollywood musical, Everyone says I love you (the title itself is a homage to the Marx Brothers). Interestingly, it's all set up by the music: a scene before features an instrumental snatch of 'You brought a new kind of love to me', the song each of the three Marx Brothers sing in order to impersonate Maurice Chevalier in Monkey Business, next a big musical set-piece opens with a couple of dozen dancers, all dressed as Groucho, singing 'Hooray for Captain Spaulding' (from Animal Crackers) in French. Then we have Woody Allen and Goldie Hawn, talking intimately with Groucho disguises on, in the midst of a party where everyone has a Groucho mask. The dialogue itself is very Woody Allen but just a few times Woody throws in a few smirks and raised eyebrows that are just perfectly Groucho, betraying exactly the same obsessive watching and re-watching of old Marx Brothers films as Eddie Murphy with his Richard Pryor records. Curiously, when a comic pays his respects to another comic, he borrows the style and mannerisms (form) but not the actual gags (content), whereas a band will tend to cover another band's song (content) but will be expected to do so in there own style (form). Of course, there is a certain taboo amongst stand-ups around 'stealing' another comic's material and doing impressions is a common feature in comedy routines, whereas musicians are expected to develop their own style, their own 'voice', but playing covers is accepted as educative. However, what happens in a hypothetical situation in which Eddie Murphy is doing an impression of Bill Cosby chastising him for using swear words in his act, and as Cosby chastises Murphy he starts to impersonate him, so we have Murphy impersonating Cosby impersonating Murphy. Or what if the specific bit of Murphy's act that Cosby has a problem with is the bit where he does an impression of Bill Cosby, so we end up with Murphy doing an impression of Cosby doing an impression of Murphy doing an impression of Cosby ad infinitum. We find ourselves back in the territory of Douglas Hofstadter's 'strange loops'. How might this work in music? Already, with Allo Darlin', we have a kind of meta-music, a music with other music nested within it. If I (or, even better, Johnny Cash) were to then cover 'Heart Beat Chilli' with its reference to 'I Walk the Line', then we reach a kind of meta-meta-level, but still not the kind of tangled hierarchies we find in Gödel, Escher, Bach. 
These kinds of Epimenidean structures turn up a lot in marxism - Vladimir Tatlin's Escher-like Monument to the Third International springs immediately to mind. Or take Zizek's analysis of the relationship between politics and economics (in In Defense of Lost Causes), such that politics is determined in the last instance by the economy, but by an economy which is itself a political-economy, an economics imbedded in, and imbued with, politics. Of course, Zizek delights in seeming paradoxes like this, but it is interesting to see these kind of self-referential loops turn up even in the critics of marxism. Doesn't Simone Weil's image, for her critique of the logic of proletarian auto-liberation, of a horse riding itself, recall somewhat Escher pictures such as 'Drawing Hands'?
