The Summer Opera Theatre opened its season last night at Hartke Theatre with Puccini's "Gianni Schicchi" and "Suor Angelica." Both showed what wonders can come from modest opera productions when taste and talen are in evidence. And one of them boasted the birth of a star.

Soprano Jung Ae Kim has been heard much locally, but never to such ravishing advantage as in this sweet Puccini role. Suor Angelica is a young nun whose last sin is suicide yet whose love and innocence bring her salvation in a moment of final bliss; she is also one of Puccini's most fragile roles, musically problematic and dramatically almost cruel in its brevity. In Kim's performance, there was immediacy in her pain and transfiguration, splendor and pathos in her voice, a lyric instrument with dramatic reserves which she can summon and shade at will.

Her "Senza mamma" was a model of simplicity and truth on stage. Throughout the score, the young soprano displayed a mastery of legato, subtle portamento, and a habit of slightly flatting certain phrases for effect. Her diction was exemplary. Jung Ae Kim has studied with Licia Albanese, and she obviously has learned her lessons well.

Sally Stunkel was a commanding Abbess, while Ann Hart sang the role of the Princess with stern intentions but too light a timbre. The cast of nervous novices and singing nuns was fine, better in music than in Italian. The staging by John Lehmeyer was sensitive and intelligent, and the ecstasy of the final scene was Teresian in spirit.

"Gianni Schicchi" was just very cute by comparison, but that is no small achievement. Puccini's comic gem has been updated by F. Robert Lehmeyer from Dante's time to Mussolini's, and works well: the plot centers on a dead man's will, and property law has not grown much since the Renaissance. The title role was sung by Lawrence Thomas with a wooly baritone and nasty charm. The young lovers were Teresa Ann Reid and Philip Bologna, the latter making an impressive professional debut with this opera. The rest of the ensemble, from the greedy relatives to a Mafioso lawyer, is extremely funny.

The two operas are repeated on July 17, 19, 22, 24, and 26. Now in its third year, Summer Opera is good opera for any season.