They may come from present-day Philadelphia , but you could be forgiven for mistaking Fern Knight for a late-’60s British folk revival band. Warbly hints of psychedelia and electronic phasing mingle with gossamer, pastoral melodies played on harp and cello along with guitar and violin. At the heart of the album is the voice of Margaret Wienk, bewitching as a woodland nymph as she sings mysterious songs with titles such as “Hawk Mountain,” “Sundew” and “Magpie Suite: Prelude, Part II, Part III.” With its lush and dreamy music, Fern Knight sounds as if it could have been on the road with the Incredible String Band circa 1970.