NEW YORK (AP) — Come and take a trip to the giddy birth of rock ‘n’ roll through the eyes of one of its pioneers — Brenda Lee. The “I'm Sorry” and “Rockin’ Around the Christmas Tree” hitmaker who shared stages with both Elvis Presley and the Beatles is a guide to those heady years in “American Masters — Brenda Lee: Rockin’ Around,” which premieres Monday on PBS. “That era can never be repeated again,” she tells The Associated Press on the eve of the broadcast.