Richard Thompson has said that “Beeswing,” his plaint of love for an untamable woman, is loosely based on Briggs, the elusive singer-songwriter from the British Midlands who drifted from public view not long after this 1971 release. The album’s a gentle suite of Celtic folk rounds, evoking country folk and stone-walled paths, ancient rites and carnival days. Briggs has an appealing yodel that she uses when trilling over wide-spaced notes, and a husky, longing vocal quality that suits her spare and haunting tunes. Despite being largely lovely, there are couple of clunkers that keep the album from reaching its full potential, but the good stuff is so good you can forgive ’em, and wish she’d stuck around and collaborated with some of the British folk-rock royals who adored her. Her version of “Beeswing,” for instance, would be astonishing.