Jason Vieaux isn't the sort of guitarist who needs guest artists in order to present an engaging recital. Even so, this frequent visitor, presented Sunday by the Philadelphia Chamber Music Society, had the young soprano Sarah Shafer for performances of John Dowland songs and Benjamin Britten folk music arrangements that became charming interludes between more challenging works.
Overall, the recital explored the fascination that 20th-century Britten had with the melancholic 16th-century Dowland. Four of Dowland's more popular songs, with Shafer's youthful voice accentuating the music's straightforwardness, laid the foundation for Britten's cerebral 1963 Nocturnal After John Dowland, which the composer himself admitted was rather remote. The theme and variations format is backward: The theme arrives at the end of eight variations that are so far flung you aren't sure they belong in the same piece.