On my last night at this year’s SXSW, I was a guest at a very private party — a surprise sixtieth-birthday bash for Bobby Whitlock, who was, for a time, at the center of everything as a vocal-keyboards sidekick with Eric Clapton in Delaney and Bonnie and Friends, on George Harrison’s All Things Must Pass and as the Memphis-soul factor in Derek and the Dominos. By the end of that party, Whitlock, now living in Austin, was handing out presents at a piano, singing the Dominos’ “Bell Bottom Blues” and playing the famous instrumental coda to “Layla.” Whitlock and his wife, singer-saxophonist CoCo Carmel, close their fine new record, Lovers (Monney Productions), with a version of “Layla” that is part slow dance, part rave-up. But it is the combined heat of Whitlock’s rugged white-Dixie-R&B howl and Carmel’s gospel-siren vocals in new songs such as “Best Days of Our Lives” and “Ain’t No Other Baby” that take you right back to 1970, minus the nostalgia.