Here are links to individual singer websites as well as YouTube videos of great singers.
Lawrence Brownlee, tenor
This guy used to beat me at NATS every year when I was an undergraduate. Now I don't feel so bad...count the high C's in this aria!
Patricia Racette, soprano
I saw Ms. Racette sing all three leading soprano roles in Puccini's Il Trittico at the Met last year. Outstanding singer/actress.
Jonas Kaufman, tenor
Kaufman is currently taking the opera world by storm. His rich, baritonal color is rare in a tenor. Here he sings the famous Flower Song from Carmen.
Susan Graham, mezzo-soprano
My favorite mezzo singing Reynaldo Hahn's A Chloris.
Joyce DiDonato, mezzo-soprano
Wow. Perhaps the best Rossini mezzo singing right now...
Nathan Gunn, baritone
A great example of an opera singer "crossing over" into musical theater. Although, these Rodgers and Hammerstein roles were written for classically trained singers.
