Countertenor Anthony Roth Costanzo and mezzo soprano Joyce diDonato actually share some repertoire, as both sing many of the same Handel arias. When Joyce suffered a minor injury recently, Costanzo was in town rehearsing Britten's opera A Midsummer Night's Dream.(at the Wheeler July 20 and 22). He and pianist Patrick Summers agreed to put on a recital to replace Joyce's, even though both are incredibly busy with their many other performing and teaching obligations. He talks with APR classical host Chris Mohr about his recital.