Because the new sensibility demands less ‘content’ in art, and is more open to the pleasures of ‘form’ and style, it is also less snobbish, less moralistic — in that it does not demand that pleasure in art necessarily be associated with edification. If art is understood as a form of discipline of the feelings and a programming of sensations, then the feeling (or sensation) given off by a Rauschenberg painting might be like that of a song by the Supremes. The brio and elegance of Budd Boetticher’s The Rise and Fall of Legs Diamond or the singing style of Dionne Warwick can be appreciated as a complex and pleasurable event. They are experienced without condescension.
– Susan Sontag, “One Culture and the New Sensibility,” 1965
[I’ve been under the impression for a long time that Sontag mentioning the Supremes and Dionne Warwick was a Big Deal. To this McLuhan/Aesthetics of Rock fan, it all seems a bit so-what to me, but perhaps in context, in 1965 — inside the halls of academia? — assigning value to the Supremes did signal some kind of line being crossed. I don’t know. I’ve also heard that Sontag later shrugged off whatever affinities she once expressed for pop, though I’ve never seen the evidence of such.]
Robert Rauschenberg, “Signs” (1970)
RockCritics.com 
In his takedown of Sontag (included in The Dustbin of History), Greil Marcus quotes Sontag from a Time interview, 10/24/1988: “As for equating high and popular culture, she explains: ‘I made a few jolly references to things in popular culture that I enjoyed. I said, for instance, that one could enjoy both Jasper Johns and the Supremes. It isn’t as if I wrote an essay on the Supremes.” That always sounded pretty dismissive to me.
You’re right, Devin, thanks. I would have read that some years ago, and simply forgot the source. I did think of Marcus’s takedown of Sontag while posting this, but didn’t feel the need to pursue further evidence on the subject–don’t think I need his dismissal (though I’m sure he helped) to convince me that she’s basically full of shit here (I won’t dismiss her work entirely, not being familiar with hardly any of it). Even the original quote from ’65 is a bit laughable, especially the line “can be appreciated as a complex and pleasurable event.” See Nat Hentoff’s throwaway line about Ralph Gleason and “pop culture” in this post to begin to understand why.