Many professional singers never learn proper techniques and never fully develop their voices. Phyllis Curtin, renowned soprano and a visiting artist in the Learning From Performers Program, yesterday told a master class she taught in Winthrop House.

Curtin has premiered more operas than any other American soprano. Her career has included frequent appearances with the New York Metropolitan Opera, the Vienna State Opera and Milan's La Scala Opera Company.

Yesterday Curtin outlined the three "basics" of opera singing: proper breathing, posture and tone control. She added that many singers do not receive adequate training in these skills.

Curtin, currently head of the voice department at Yale, then demonstrated how proper application of these "basics" can enhance a singer's delivery, by offering six students in the class specific instructions.

"Her comments make everything click," Ellen Burkhardt '79, who sang a Mozart piece for the class, said yesterday. Burkhardt said Curtin's comments greatly helped her performance.

The student performers were chosen by audition before a three-member selection committee composed of members of the Music Department.

Curtin said the human voice is an instrument which, with proper training, "grows up with the performer," and reaches its peak development when the singer is 45 to 55 years old.

Singers who do not receive proper training "sing for six or seven years and then are gone," she added.

Curtin said her vanity is wounded when people ask if she is "still singing."

"I never stopped singing," she said, adding that her voice is now capable of performances it could never achieve before.

Curtin will teach another master class today from 3 to 5:30 p.m. in Winthrop's Tonkens Room.