The first words out of Antony Hegarty's mouth when his name was announced at Sept. 6's Mercury Prize Awards? ''I think they must have made a mistake.'' Indeed, though the prestigious U.K. prize is known for idiosyncratic choices past winners range from critical darlings Primal Scream and PJ Harvey to M People (yep, we don't know them either) he is, to say the least, a left-field choice. For one, though he was born in England, the 34-year-old New York resident has lived in the States since 1983; for another, Antony and the Johnsons' winning album, I Am a Bird Now, an arresting mix of Hegarty's Nina Simone-ish vocals and operatic, piano-laden balladry, is truly unique a hothouse orchid in a field of rock sequoias (Coldplay) and hot young saplings (Kaiser Chiefs, Bloc Party). Some theorize that those nominees canceled one another out; Bloc Party singer Kele Okereke disagrees. ''There are certain bands,'' he admits, ''that if they had won, I think I would have lost my faith in the British media. I'm glad it went to someone who deserves it.... He's just a really, really great artist.''