Catherine Martin’s mezzo has warmth and shimmer, as well as a degree of cut that lends distinction to her interpretation of classic lyric roles. Last summer she had a success at Glimmerglass Opera as the Composer in Ariadne auf Naxos, and this month she turns up at Dayton Opera as Sister Helen Prejean, the nun who helps a convicted killer discover grace in Jake Heggie and Terrence McNally’s Dead Man Walking. An alumna of the Houston Grand Opera Studio, Martin first studied the role a few seasons ago, when she covered Joyce DiDonato at HGO. “I got to meet Sister Helen and talk to her about the book,” says Martin. “I think the opera is important, because it shows the fault of Sister Helen as well — maybe she could have reached out to the victims’ families more. Even she says, ‘Maybe I should have done more.’ Anyone who goes to see it and says that Jake Heggie is for or against capital punishment misses the point. You need to make your own opinion about it.”

Martin studied voice at the University of North Texas and the University of Cincinnati College–Conservatory of Music. There was never any confusion about whether she was a mezzo or a soprano, but, she says, “Repertory is another story. Unless you’re a Cherubino–Rosina-type mezzo, it gets a little hazy on what you should be singing. I’m trying to get my hands on Octavian. I feel that would be great for me right now. I love singing Britten, too, because there’s not such a prototype on the sound that people are expecting.”

Martin has done well on the competition circuit: she was a winner of the 2011 National Opera Association Competition and a finalist in the 2012 George London Foundation Competition. Her lucky aria on the circuit has been La Favorita’s “O mio Fernando.” “Sometimes I do the Composer or Octavian,” she says. “I try to present one English piece, like ‘Give him this orchid,’ from The Rape of Lucretia. I would love to sing Charlotte in Werther, and I had the letter aria prepared, but it’s so long that I felt people wouldn’t call for it.”

Martin’s six-foot stature is a strong component of her naturally striking stage presence. She works hard to stay fit. “You never want to sacrifice sound for how you look,” she says, “but it has to be an element. I have to work out and watch what I eat, and it’s hard with travel. When people see me on a plane with my score open, trying to work, and they say, ‘Oh, what’s that?’ I say, ‘Well — it’s music.’ And so often they say, ‘You don’t look like an opera singer.’ So I try to get rid of that stigma.”