Two rarities during the musical performances on “ Saturday Night Live ” this weekend: actual rock ‘n’ roll was performed. Even rarer than that, Thomas Jefferson was quoted — prominently and at length — in the spot where a guitar solo might have gone. During Brandi Carlile ‘s performance of the hard-rocking, U2-styled “Church & State,” Carlile offered a spoken recitation between choruses about the title subject. Viewers might have thought the words sounded familiar, but hard to exactly place.