One thing you can say about Jon Anderson, the totemic former Yes frontman: the gloriously voiced little weirdo was emblematic of everything that came to be called “prog rock.” He wore stage suits with angel wings. His lyrics — a linguistic salad of pixie mythology, peace anthems and, of course, space travel — were craftily phrased mumbo jumbo that made zero sense even to his bandmates. And his arc-of-the-twilight melodies and songs were enough to make you believe in God.

Or, if you hate that sort of thing, it was all enough to make you invent punk rock.

Anderson has been gone from Yes for a while now, which seemed to make little difference to Friday’s sold-out crowd in the MGM Grand Theater at Foxwoods. For one thing, Yes still includes core members Steve Howe (guitar), Chris Squire (bass) and Alan White (drums), with Howe’s Asia buddy, Geoff Downes, fluently handling keyboards. And, as indelible as Anderson’s contributions were, Howe and Squire’s respective instrumental acuity and tones, songwriting chops and vocal harmonies have all along been equally responsible for Yes’ success and longevity.

For another thing, Friday, the band performed complete and front-to-back versions of two of the greatest rock albums ever, “Close to the Edge” and “The Yes Album.”

How cool is that? (At other stops on the tour, they’re even throwing in the wonderful “Going for the One” album, but casino time constraints ...)

Enjoyment of Yes, at this point, comes down to your soulful investment in the “integrity” of the group and whether, for purity purposes, you can accept the latest singer, Jon Davison.

The most important thing is: close your eyes and Davison sounds EXACTLY like Anderson. Not only does he hit the notes and capture the phrasing, he has that precise, reedy-thistle characteristic that millions have adored for over 40 years.

In Friday’s context, with Howe, White, Squire and Downes nailing the music and vocal arrangements in studious but joyous fashion that belies how many hundreds of times they must have played this stuff in the past, the fact that Davison is spot-on counts for something. It counts for a helluva lot, in fact.

Still, onstage, Davison seems slightly out of place. He’s clearly several years younger than his colleagues, for one thing. Also, coming from a past that includes a stint in a Yes tribute band, it seems he can’t decide whether to completely mimic Anderson’s grandiose, all-are-welcome arm gestures — or stand awkwardly with a beatific smile on his face.

Well, life ain’t perfect and band members come and go. Perpetual change, if you will.

This, then, is what must pass for Yes in 2013 — and they still and wonderfully provide the time/space magic that the exultant and surprisingly diverse crowd already knew. The music is gorgeous and amazing and eternal.