Oscar Peterson’s series of recordings for Hans Georg Brunner-Schwer during the 1960s and early ’70s are one of many high points in his long career. With George “Jiri” Mraz on bass and Ray Price on drums, Peterson’s flashy romp through “I Love You” (complete with a humorous detour into the opera “Pagliacci”) and mid-tempo walk through “All of You” salute Cole Porter in style on Walking the Line. “Rock of Ages” isn’t the old hymn but a lively, gospel-inflected Peterson original that will easily get any congregation swinging and swaying to the music. His mastery of the ballad form is heard in his sensitive interpretation of “Once Upon a Summertime,” which showcases Mraz’s gorgeous tone, as Price sits out this one.