The Mostly Mozart Festival is in its 17th season in New York - a highly respected, reasonably priced part of the Big Apple's summer season. It has spawned several similar festivals around the country, including a week-long stint in Washington with the same forces, and a festival in San Francisco that uses something close to the same format. New examples pop up every year.
People never tire of hearing Mozart, and why should they? His communicative power is unique. The variety and quantity of his work throughout his brief life constitute an exceptional pool of music from which to cull a season. But there is always the danger that a staleness will creep into a festival devoted to one composer. In the past, this has been skirted by including a second composer's works in a festival-within-a-festival. A few years ago it was Beethoven, before that Haydn. Yet even that idea slips into tedium if only the popular works of any composer are offered.
In truth, at Avery Fisher Hall, where the festival holds forth six nights a week through Aug. 27, programming has often gravitated toward a re-airing of the more popular works. Certain ''name'' soloists were chosen more for box office draw than for meaningful contribution to a program. This year, music adviser Gerard Schwarz has tried to give audiences a little less Mozart and a few more soloists (there are often two per program). Also, the guest-conductor list looks more like a festival lineup than it has in the past. In the non-orchestral programs, the selection of chamber groups has also been a comfortable mix of known as well as respected. And, of course, the perennial Alicia de Larrocha was around on three occasions: Mostly Mozart just wouldn't be the same without her.
Mr. Schwarz has improved the day-to-day level of performances and performers. This season the roster is as strong as I can remember - with such conductors as Julius Rudel and Leonard Slatkin; pianists such as Miss de Larrocha (for two concerto appearances), Emanuel Ax, Garrick Ohlsson, Horacio Gutierrez, and Richard Goode; cellists Lynn Harrell and Yo-Yo Ma; oboist Heinz Holliger; clarinetist Richard Stoltzman; and flutist Jean-Pierre Rampal. The programming has broadened out to include Brahms, Tchaikovsky, and Richard Strauss, as well as music by those who lived nearer to Mozart's time.
Even on stage things look different. The orchestra now sits in true Classical style - the first violins to the conductor's left (and the basses behind them), the second violins to his right, with the cellos and violas in between. It is surprising it took so long for anyone to think of this - Mozart wrote his music for that seating, and the improvement in sound is striking.
The difference in the quality of the orchestral playing is also striking. This ensemble - after years of serving as something like a sound track for a list of visiting celebrities - is suddenly being treated as a worthy ensemble, and the members are playing as if their job was the most important one in the world. This is not to say that ensemble is impeccable or that they are now a great orchestra, but with this huge change in attitude under Mr. Schwarz's deft guidance, who knows what could come of it? Perhaps New York could cultivate its own year-round chamber orchestra!
Now, the task at hand is to make Mozart the real feature of this festival. There is so much music to choose from, and with this newfound enthusiasm even the famous works will sound more engaging, more communicative.
Quality has been high in what I have spot-checked of this season. Most recently, Mr. Schwarz had the orchestra tackle the Brahms A-major Serenade. It did it with rich tone, sensitive wind playing, and a genuine sense that something important was passing by. Earlier that evening, Henryk Szeryng offered a superb account of the Bach A-major concerto and a loving perusal of a so-called Mozart Concerto No. 7, which, while in all probability a bogus composition, unfolds pleasantly in a suitably Mozartean way.
Before that, I had heard an evening that boasted Mr. Ma's outstanding performance of Tchaikovsky's ''Rococo Variations'' (discussed in this column July 20). A few weeks back, Julius Rudel mounted the Mostly Mozart podium in a rare non-operatic stint in New York. He conducted Haydn's Eighth Symphony (''Le Soir'') from the harpsichord - something few conductors today can or dare do. He was joined by Miss de Larrocha for Mozart's K. 459 concerto (F major, No. 19), and together they were enchanting in this most upbeat of the composer's concertos. Mr. Rudel's Beethoven Second Symphony was a thing of vigor, style, and often great beauty. Mr. Rudel took all the repeats - a welcome choice - and in all offered a typically stylish, confident, ebullient evening of musicmaking.
Mr. Schwarz's Brahms Serenade proved enchanting, too. This gifted trumpeter-turned-conductor grows by the day in confidence and stylistic awareness. His ability to get this orchestra to play so well is but one proof that his career switch was a wise one.