David T. Mortensen will serve as chairman of the Utah Opera board of trustees, with Clark D. Jones as president.

Mortensen joined the Utah Opera board in 1987 and served as president for two years prior to his election as chairman. He is president of Mortensen Food Productions, and serves on executive boards for the State Arboretum at the University of Utah, Planned Parenthood and the Special Exhibitions Council, Utah Museum of Fine Arts. "It will be my goal to maintain the stability of the (organization), to keep it moving forward by making reasonable expansion plans, and to keep the board working together as a unit toward those ends," he said.Jones is chairman and chief executive officer of JB's Restaurants, Inc. He also has served Utah Opera as a trustee since 1987. He has been president of the Sugarhouse Rotary Club and served the boards of The Children's Center, Utah Lung Association and the Cottonwood Alta View Hospital Foundation.

Other new board members include: John A. Becker, David Bronson, Robert Gross, Frank R. Pignanelli, Steve Schroeder, Bruce Spotleson, Terry Summerhays, Jackie Nokes, Ronald Ockey, John L. Valentine, and Boyd Christensen.

- TEN YOUNG UTAHNS have claimed prizes ranging from $50 to $300 in this year's Utah Symphony Youth Guild Competition, concluded last week in Symphony Hall. Winners were:

ELEMENTARY: First - cellist Ryan Swigert; second - flutist Jillana Watson; third - violinist Lexye Lund.

JUNIOR: First - pianist Elena Cho, violinist Jason Swigert (tie); second - violinist Jenny Oaks; third - violist Rebecca Anderson.

SENIOR: First - pianist Jennie Watson; second - pianist Marquessa Bullock; third - violinist Victoria Ferris.

In addition the first-prize winners in each division will have the opportunity of soloing with the Utah Symphony during its 1991-92 season. Winners were selected from 45 entrants in two days of judging. This year's competition was chaired by Youth Guild chairman Julia Moore.