Still Believing in Yesterday : O.C. Pop Music Review: Paul McCartney entertains a full house at Anaheim Stadium with all the old songs played the old way.

Paul McCartney, newly minted eco-activist and animal rights crusader, had vegetarian hot dogs put on the snack bar bill of fare Saturday night at Anaheim Stadium.

As it turned out, any meat lover who sampled one of Paul’s veggie dogs was taking a more adventurous approach to the evening than the maestro himself.

McCartney’s show was unrelenting in its conservatism. Playing for a full house of about 50,000 Boomers and very few younger listeners, the former Beatle, at 50, offered a steady diet of musical comfort food, a concert given almost entirely to reassuring the old fans with old songs, played the old way.

If you’re going to preserve a body of rock music as if it were sacred writ, the Beatles catalogue, which accounted for 18 of the show’s 32 selections, stands first in line for canonization. But a concert should venture something, and McCartney (who also gave like-the-record readings of seven of his post-Beatles hits and six songs from his sub-par new album, “Off the Ground”) merely re-created his past instead of using it as a taking-off point. (If you’re adding, the 32nd song was an acoustic cover of the Elvis oldie, “Good Rockin’ Tonight.”)

We’re not saying that he had to reconstruct every song; just enough to show that his still-impressive musicality and obvious pleasure in performance remain informed by a restless spirit. Think of Eric Clapton’s unplugged “Layla.” Think of the reconsideration and revision of past material that is an ongoing, in-concert process for McCartney’s occasional songwriting partner, Elvis Costello.

McCartney’s wondrous natural talent remains virtually intact. One had to pick very small nits to find any falling off from those recordings he was replaying. There were just a few vocally strained moments toward the end of a generous 2-hour, 20-minute show in which McCartney took nary a break from singing. Mainly, he and his band delivered the notes we’ve known for all these years, and that’s no small accomplishment. The only time he clearly balked at matching his younger self was when he chose a lower, safer flight pattern rather than risk soaring into the “blue suburban skies” refrain of “Penny Lane.”

Evidence of conservatism came in the show’s prevailing mellowness. McCartney (who played the same set as he had three days before on his American tour’s opening night in Las Vegas) could have rocked out a good deal more, especially during a long mid-show sequence of ballads and gentler material broken only by one of his all-time career stiffs, the new “Biker Like an Icon.”

He waited almost to the end of the show to stretch a song past its familiar boundaries, finally squaring off with ex-Pretender Robbie McIntosh for a high-powered double-guitar workout during “Sgt. Pepper’s Lonely Hearts Club Band.” “Magical Mystery Tour” would have served as an ideal vehicle for an excursion into the psychedelic, but McCartney cut it off after just a hint of piano exploration.

As a social activist, McCartney made his big statement in a 10-minute introductory film that cut from a review of his musical rise to an unsparing sequence depicting brutality toward animals. On stage, he was his usual enthusiastic, upbeat self, showering the audience with chirpy amiability and skipping the political pronouncements. Given the naively rah-rah approach to social commentary in his “Off the Ground” material, that was for the best.

McCartney did allude twice to the verdicts in the Rodney King civil rights case that had come down earlier in the day. He introduced “Peace in the Neighbourhood” as “particularly appropriate today, I think” and he kicked off a rollicking encore reading of “I Saw Her Standing There” by proclaiming: “I think with the news we got this morning, we have something to celebrate, so let’s do it right now.”

If McCartney’s audience has grown so conservative as to forget that innovation and exploration were the Beatles’ hallmark, this warmly reassuring pat on the back of a concert gave them reason enough to celebrate. But those seeking fresh ideas and spontaneity in a rock show can only conclude that McCartney’s current approach risks giving credence to the most mean-spirited lyric John Lennon ever sang. That’s the one in which he pointed at his former partner and sneered: “The only thing you done was yesterday.”