Anna Prohaska’s recital takes us into the moss-carpeted dreamworlds of Ariosto, Ovid, Shakespeare and Tasso. The theme is transformation, by love or magic or a combination of the two. Arcangelo’s instrumental playing is reliably interesting, sometimes too interesting (Jonathan Cohen is not a ‘less is more’ director). But the most effective enchantment occurs when Prohaska stops trying to fit her dryish, coolish voice into a Patricia Petitbon-shaped presentation box.