The Stockholm duo Ak-Momo creates music that soothes the soul even as it troubles the mind. Mattias Olsson uses antique electronic instruments such as the optigan, orchestron and mellotron to craft gorgeously melodic but vaguely disturbing backing for Ak von Malmborg’s pixieish vocals, which suggest Joanna Newsom and (by extension) the young teenage Kate Bush, with traces of Björk and a strange but undeniable dash of Billie Holiday. It’s all very pretty, but slightly askew. Malmborg’s tale of making love under the night sky on “Only the Stars” might be a fond remembrance of a delicious tryst, but it could just as easily be the obsessive fantasy of a disturbed mind. When Olsson incorporates Martin Denny-style exotica into the backing tracks on “Your Mother’s Faith” and “World Traveller,” the results seem even more unearthly. Return to N.Y. is a fascinating document, a radio broadcast from another plane of existence.