There’s something about seeing a Doc Watson show that’s akin to being inside a time capsule.

Watson never changes much — the same guitar, the same comfortable clothes, the same accompanists.

But the songs are rarely the same. Watson, who turned 85 on Friday, is a living repository of American country, blues, folk, gospel and swing music as filtered through the man from Deep Gap, N.C.

And so it was that 933 people in a sold-out Jefferson Center were the ones who got the gift on Watson’s birthday.

Count Peter Rowan among them. Though Watson was listed as the headliner, he played first. Rowan and Tony Rice finished the show with their quartet. Rowan dedicated his band’s first song, “Roll On Buddy,” to Watson. Then he credited Watson as the inspiration for another song, his own “Trail of Tears.”

A Doc Watson gig is really two distinct sets. In the first half, grandson Richard Watson accompanied him on some laid-back country blues songs. They opened with Jimmie Rodgers’ “Train Whistle Blues,” with Richard Watson taking the leads.

“How do you feel about that, Merle — I mean Richard,” Watson said, by way of introducing a guitar break.

Merle, of course, was Doc’s son. He died in a 1985 tractor accident. Many in the crowd no doubt knew this. You could hear a sympathetic “aww” from several in the room.

Longtime accompanist Jack Lawrence joined Doc Watson for the second half of the set, a faster-picking affair that included Grandpa Jones’ “Eight More Miles To Louisville,” and the set-closing “Black Mountain Rag” — which Watson introduced as a song that “everyone and his brother wants to hear at some time or another.”

Watson, still strong of voice, also showed that even if he is 85, his fingers are probably still in their early 40s, as he burst through some crowd-pleasing runs.

Rowan delighted the crowd early with stories about Bill Monroe and trips on U.S. 11 through the Roanoke Valley as Rice tried to get his monitor mix correct. Once settled, Rice burned. He’s still a jaw-dropping player, weaving in elements of jazz, soul and classical music, and making it all still sound like bluegrass.

Also strong onstage was all-star mandolinist/fiddler Rickie Simpkins, familiar to many among Southwest Virginia bluegrass aficionados.