WHEN the Boston Philharmonia opens its fourth season in Sanders Theatre Sunday evening, it will perform one of the least publicized concerts in recent memory. Hard hit by the state of the economy, the orchestra decided to cut costs in the least necessary segments of the budget, and advertising was among the first to go. If things work out well, the belt tightening this year will stop before it reaches the artistic budget, but orchestra spokesmen are not overconfident.

A short way up Huntington Avenue, the Boston Symphony is also starting to feel the pinch, although in a much smaller way. That orchestra still mangoes to meet its $51/2 million budget, but not without added fundraising and dipping into unreserved capital funds. Season ticket sales have taken a slight fall, because, in the words of an orchestra spokesman, "When the economy is bad, some people hold off renewing." Nonethe less, BSO concerts, normally close to selling out, and radio and television revenue helps take up the slack.

The problem of money is not specific to orchestras, of course. Educational and artistic institutions of all sorts are the first to suffer during any period of economic instability. But the Philharmonia suffers more than most such organizations because of its newness, because of its lack of endowment, and because of the innovative kind of program it plays. This combination of factors makes it, an exciting orchestra, but also threatens its existence.

Four Concerts

The Philharmonia will only attempt four concerts this year, all of them on Sunday evenings at Sanders. If money becomes available, the orchestra will repeat each of the four programs in outlying areas which normally would not hear symphony orchestras, and also try to inaugurate a series of children's concerts. They will try to avoid last year's situation, in which they were forced to cancel the last concert of the season for lack of money.

The Philharmonia is filled with good intentions, and innovative ideas. It is a cooperative orchestra, in which the players choose the conductors and the programs. None of the members of the orchestra make their living from the Philharmonia; most of them are music teachers, or solo performers. When a concert turns a profit, they share it; more often, they con tribute from their own funds to make the concerts possible. (One member gave $500 from his own pocket to meet the rent for a performance last year.)

The man who holds much of the responsibility for the orchestra's operation is its chairman, Maynard Goldman. Goldman is a violinist who teaches at Brandies, plays in the orchestra, and acts as the performers' spokesman. He has a deep enthusiasm for the orchestra and the innovations it is attempting. "It is an opportunity for people like myself to get together and perform, to choose our own programs, and choose our own conductor" he says. "We certainly don't make our living performing with the Boston Philharmonia."

Budget

Goldman thinks that one of the orchestra's strengths is its low budget. Although the Philharmonia runs on only $65,000 a year, he notes, "We don't attempt to provide 52-week-a-year employment, or 48 weeks with 4 weeks vacation." The orchestra can subsist on almost miniscule state and foundation grants because of its small operating costs.

This year's schedule includes an interesting combination of classical and contemporary works, aided in part by a Rockfeller Foundation grant for the preparation of contemporary music. Sunday's concert, with Alexander Schncider conducting, consists of the Mozart Clarinet Concerto in A, K. 622, Stravinsky's Dumbarton Oaks Concerto, a Corelli Concerto Grosso, and the Mozart G Minor Symphony, K. 183. Later concerts will include Schoenberg's Kammersymphonie, Stravinksy's Concerto for Strings, Elliot Carter's The Minotaur, and Haydn's Oxford Symphony, all of them extremely interesting pieces.

If the orchestra has broken away from the standard concert repertoire, it has done so deliberately. "We're trying to be relevant to the community rather than to fit an archaic form," says one orchestra spokesman. The most interesting innovation is a new kind of program for children, which Goldman calls "Children's Concerts, in which we really have open rehearsals, in which children can wander up on the stage. We'll let them wander among the performers, touch the instruments, really be open."

Rehearsals

Even though the orchestra is made up of men who make their livings at other jobs-including the permanent conductor, Harvard Professor Leon Kirchner-they do not skimp on rehearsal time. "We do not go into any concert unrehearsed," says Goldman. This is true no matter how long it takes to learn a piece, and rehearsal costs can take up a good chunk of the budget. Without the pressure of thrice weekly concerts, the Philharmonia can take a more leisurely approach to music.

NO ONE would rank the Philharmonia as a competitor to the Boston Symphony, or as any threat to its existence. While the BSO has had changeable fortunes in recent years, it still maintains its predominant position, Relations between the two orchestras are good; it was the Philharmonia which introduced Michael Tilson Thomas to Boston, and the soloist in next Sunday's Mozart concerto will be the new BSO first clarinet, Harold Wright.

Although it is much easier to get a BSO ticket nowadays than it was a few years ago, the orchestra does not feel obliged to wage war on the Philharmonia, since BSO box office receipts are still healthy.

The quality of the BSO's performance, on the whole, is superior to the Philharmonia's. This is quite natural, since the members of the BSO spend full time in performing, rehearsing, or recording. The Philharmonia probably cannot break this superiority, and it doesn't really want to. The main virtue of the Philharmonia is the novelty of its programs, the looseness it has by its nature. Conductors and performers both can experiment, indulge in new ideas which the day-to-day grind of the standard concert repertoire makes no room for.

There are drawbacks, of course, to this approach. For one thing, some Philharmonia concerts have consisted of music which is not only unusual but somewhat uninteresting. Others have been performances of less than the highest quality. Naturally, performers who do not take part in orchestral concerts every week tend to be less sharp than those who do. The Philharmonia's emphasis on rehearsal is, in part, an attempt to correct for this weakness.

The existence of the BSO has not worked entirely against the Philharmonia. BSO players have occasionally filled in for Philharmonia musicians, and the BSO's professional problems may have helped increase the Philharmonia's gate receipts. The BSO is in a rebuilding phase, bringing in new men like Harold Wright to replace aging and decrepit performers.

For the moment, the Philharmonia goes on. Orchestra spokesmen are careful to emphasize that the group is not on the verge of folding, that it will be able to meet its budget. The orchestra's creditors are being generous, not pressing it to pay its bills. Nevertheless, this may be a crucial season for the orchestra. If its subscribers and ticket sales continue to increase, as they have for the past few years, it may be over the hump. If they do not, if Philharmonia audiences decrease as Symphony audiences have, the Philharmonia may be just a pleasant memory of music, dying with a dying fall.