What makes a good music festival?

Festival programs are often hard to keep vital and interesting. Nonstop crowd-pleasers are either the norm or one tends to get novelty for novelty's sake. Usually a happy medium is not achieved.

Carp as one may over this and that, it still seems remarkable that the Mostly Mozart Festival can remain so fresh and offer enough evening of solid and even imaginative pleasure in the course of its eight or so weeks.

When one looks at summer festival elsewhere in the country, one would be hard pressed, even in the fancier, grandiose locales, to find a greater selection of performers offering a greater chance of important performance than in Avery Fisher Hall during Mostly Mozart weeks.

The assumption there is that Mozart is a crowd-pleaser, and to judge by the average attendance most nights, that assumption is altogether correct. The festival attempts to keep programming varied, to avoid having the same artists performing the same works year after year -- although there is a conscious effort to return the surefire-draw artists while assiduosly introducing new and interesting talent.

This does create something of a dual festival, and even dual audiences. The crowds that turn out for an orchestral program featuring Richard Goode and Richard Stoltzman, with Alexander Schneider Conducting, are not the same crowds that turn out for a Pinchas Zukerman of Jean-Pierre Rampal soiree.

Ironically, the less glamorous names tend to offer the better concerts, unless we are dealing with such a formidable institution and paragon of excellent as Alicia de Larrocha, the pianist. Mr. Schneider's musical approach is known to chamber-music and chamber-orchestra fanciers who attend concerts with any regularity. His rather muscular, extremely highlighted yet not entirely idiomatic conducting always curries the enthusiasm of audience and orchestra -- though even he was unable to make the Mostly Mozart Orchestra sound like the virtuoso ensemble needed in Haydn's "Hornsignal" Symphony (No. 31).

And, truth to tell, Mr. Schneider does not make an ideal accompanist in concertos, because his own ideas do not often coincide with his soloists, nor is he the most pliant conductor on the podium today.Fortunately, he does not quash his soloist into submission or oblivion, so one could appreciate Richard Goode's pliancy, his eloquence, elegance, and deftly contained musical emotings in Mozart's 23rd Concerto (A major, K. 488). Likewise, Mr. Stoltzman was allowed his moments of rapturous outbursts and hauting lyricism in the Clarinet Concerton in A, K. 622.

Or course, if one had the choice between Mr. Schneider's committed partisanship and Mr. Zukerman's bland eclecticism in the accompanist context, I'm sure all but most performers would opt for Schneider. For when a violinist-conductor like Zukerman is on the podium as a soloist, he is not often the fullfledged partner he should be.

In the case of Ken Noda, the young dynamo who has attracted the attention and tutelage of such musicians as Daniel Barenboim and Zubin Mehta, the pianist needed a real partner for the fulfillment of the promise shown in his performance of the K. 449 Piano Concerto (No. 14). What we got was imagination, invention, and real hints of style that did not coalesce into anything more than a string of signposts pointing to things to come. Zukerman, who has recently eschewed the beard that had become something of a trademark, played with typical sumptousness in Haydn violin concerto.

It is in the chamber concerts that Mostly Mozart often gained true distinction. The concert opera program this season never quite took wing, despite the coaxing of the excellent Raymond Leppard. "Bastien und Bastienne" is an early Mozart work, charmingly conceived, ponderously executed here.

The idea of dialogue in English and singing in German did not entirely set well, and Phyllis Bryn-Julson took most of the opera to find her true vocal form. David Britton, the tenor, never really found his. Bass Marius Rintzler's English proved unintelligible and his singing gruff.

"The Impresario" was more of the same, though Miss Bryn-Julson had by now warned up. Ruth Welting gave a dazzling display as the tempestuous Mme, Silberklang. "The Impresario" was preceded by the overtrue to Salieri's "Prima la musica . . .," which, in fact, preceded the Mozart work in Salzburg at the world premiere of both one-act operas. The Salieri was a diligent piece; the Mozart, sheer magic.

In chamber music, one could hear Marcel Moyse, now well into his 90s, lead the Marlboro Music wind players in a thrilling account of the Dvorak Serenade and an elegant account of the Mozart Serenade for 13 Instruments (K.361). The adventurous could also hear Rudolf Firkusny, joined by the principals of the Mostly Mozart Orchestra, in a program that featured the quartet-and-piano version of Mozart's K. 414 piano concerto. While Firkusny was adept at keeping the balance needed, without overstressing the piano against such slender forces -- and how often does one have a chance to hear the work this way -- the rest of the program was not quite so novel, nor was it especially well executed.

The wind players fared better than the string players, and in the opening Quartet K. 478 this was particularly discouraging, since Firkusny's playing proved especially insightful, delicate, and communicative.