New York — Puccini's La Boheme Directed by Wilford Leach. Linda Ronstadt's dip into opera - Puccini's ''La Boheme'' - was the brainstorm of someone at Joseph Papp's New York Shakespeare Festival Public Theater. Had that someone really thought things through, it would have remained an idea. Yet Miss Ronstadt had scored a personal triumph in the New York Shakespeare Festival production of ''Pirates of Penzance'' (later committed to film). Her new style of singing - as heard in her latest album, ''Lush Life,'' and featuring the Nelson Riddle Orchestra - has been justifiably acclaimed. Therefore, the thinking must have gone, Puccini would supply a promising new vehicle for her.
Miss Ronstadt knew early that she was in trouble, that the areas of her imposing voice that would be tapped in ''La Boheme'' were ones she had hardly ever used in her rock - and now her pop - career. In fact, so tenuous was her singing (and so vague her projection of words) one sensed she was profoundly, desperately ill-at-ease throughout her performance.
Clearly, her loyalty to the festival is deep. How else can one explain the fact that she will, for the rest of the month, put her all-too-evident weaknesses out on public view three times a week? The inner fortitude that allows her to do it is extraordinary, and for that sort of demonstration of loyalty in a time when that quality is in scarce supply, Miss Ronstadt cannot be praised highly enough.
Fortunately, Miss Ronstadt could not be singled out for the only error in judgment, since there was very little about this idea - putting Puccini on in a small theater with popular and Broadway voices - that was carried through with any real attention or imagination.
As actors, the cast members were pretty much left to their own devices throughout the evening, because director Wilford Leach had not scratched the surface of the drama to bring the characters to life. As singers, they were not guided by a sure enough musical hand to help make the nightly task of singing opera - albeit with a 12-piece theater band - easy: Conductor and musical director William Elliott's tortuously slow way with the score would not be accepted by the finest opera singers in the world. With the voices at the Anspacher, the problems become insurmountable, even with the aid of body mikes. (When Vincent Fanuele conducted, the tempi were fairer to the performers.)
An intimate ''Boheme,'' done in a superior English translation, with a small orchestra, should have been a lovely thing. The audience was so close to the performers that it could easily have become helplessly involved in the touching tale of love and poverty. But because of the lack of a true sense of purpose, what worked in the two performances reviewed did so because the individuals were such convincing performers.
To make a pop-voiced ''Boheme''valid, each performer had to find his or her way to connect with the character and sing the role. Cass Morgan, the Musette, did just that. Her husky, chesty voice encompassed the range of the celebrated ''Waltz'' well, and she brought the moment vividly to life in every way. Because Mr. Leach treated her later appearances so heavy-handedly, she could have been accused of overplaying, but her innate warmth came winningly through in spite of the staging.
Howard McGillin's Marcel also found its own reality, albeit a bit too unrelentingly fierce in temperament, and he sang the role with fervor. Of the two Rodolfo's, Gary Morris had the more naturally beautiful voice, and David Carroll's the better trained. Mr. Morris's acting abilities proved rudimentary at best (an ingenuousness that could have been impressively exploited); Mr. Carroll's was the best-acted Rodolfo this critic has yet to encounter in any theater or opera house. Patti Cohenour's Mimi was a thing of delicacy, simply but elegantly sung, and sweetly acted.
Throughout both evenings, one was questioning the purpose of the entire exercise. If it was to bring an intimate ''Boheme'' to life, why not have used operatically trained voices? If it was to translate Puccini to a more popular idiom, why not have transposed to help these singers, and not been so slavishly tied to the Puccini score?
Michael Staorbin's orchestrations often captured the flavor and color of the large score, but to what final avail? The sets (Bob Shaw) and costumes (Jane Greenwood) spoke of the 1890's - but, for the ladies, too tastefully and elegantly so. The English translation (by David Spencer) was at times commendably innovative, but too constantly changed plot and details and resorted to flat-footed poetry and trendy jargon, rather than sticking to the ideas found in the original Italian libretto.