The female half of the pair was Kiera Duffy, a brilliant soprano with a lustrous edge that sets it apart from the high-altitude norm. Vocal fans tend to equate soprano acrobatics with the baroque and bel canto periods, but I am willing to bet that the demands of Strauss’s Brentano-Lieder Op. 68 are even greater. This was wonderfully luminous and fluid singing, laced with Rosenkavalier charm.
-National Post, Canada, August 6, 2011