A Trio That Plays for Keeps : With founding member Menahem Pressler still anchoring the piano, the Beaux Arts Trio will celebrate a milestone at Ford Amphitheatre.

Few chamber groups manage to last as long as 40 years, much less remain at the top of the heap for that long. But among the lucky ones count the Beaux Arts Trio, which celebrates its 40th birthday this year.

To commemorate the anniversary, the current trio, pianist Menahem Pressler, 71, violinist Ida Kavafian, 43, and cellist Peter Wiley, 40, will duplicate the original group’s very first program--all Beethoven works--Monday at the John Anson Ford Amphitheatre and appear a day later in a different program with the Los Angeles Philharmonic, led by Sian Edwards, at the Hollywood Bowl.

“When we started, I didn’t think the trio would turn into a career,” recalled pianist Pressler, the only founding member still active in the trio. “I knew it would be hard work, but I never imagined it would entail blood, sweat and tears. When you really go inside the music, as we did, that’s a difficult affair.

“Today’s groups are much easier [on themselves]. They have three or four rehearsals, then after the fourth, they ask, ‘What is there to rehearse?’ They know it already.”

Pressler was speaking from his home in Bloomington, Ind., where he has taught at Indiana University for exactly as many years as the trio has existed.

Originally, he and violinist Daniel Guilet were recording chums who decided to play trios for fun. They enlisted cellist Bernard Greenhouse, one of Guilet’s friends, to complete the group.

After its debut at the Berkshire Music Festival (now known as the Tanglewood Festival), offers came pouring in. “But ones in little towns that you can’t find on the map unless you have a very large map,” Pressler said.

“Those were high school auditoriums. We would play each one billed as a solo group. When they heard we were a chamber group, well, they would think it’s medicine: You know it’s good for you, but you don’t have to like it.”

Still, they gained a lot from the experience. “It gave us the opportunity to work, to establish a group with a face, with a character, not just three players playing together, who start together and finish together,” Pressler said, “but a group that works out a conception so that everyone’s feelings and expressions would be a part. The outcome would be bigger than the input of the three. That was the Beaux Arts Trio.”

Pressler said he felt “very lucky” to be included among the three. Guilet had had his own quartet and had risen to eminence as concertmaster of Toscanini’s NBC Symphony. Greenhouse, who had studied with luminaries such as Emanuel Feuermann and Pablo Casals, had experience in chamber music, too. “The one who had the least experience was I,” Pressler said.

“We all had different training. But what we did have in common was an idea. Guilet brought insight into certain music, like Beethoven, the French masters. Greenhouse had the most beautiful sonority.

“My contribution? It is very hard for me to say. The piano seems to be the heart of the trio because the balance is determined mostly by the piano. Also, many of the impulses are given to the piano. It is the first of equals--in the writing. I will also say one other thing which I seem to have had in abundance was energy and enthusiasm.”

Pressler called the experience “a second kind of training--learning to envision a whole piece from beginning to end, not just the lovely places and let it go in between. I learned to play every second.

“The other thing was, here I had people to share a success with, and also a defeat. Of course there were defeats. We would come to a little town in Kansas. I would come on stage and there’s a little upright piano. When I asked, ‘Where is my piano?’ they would say, ‘There it is. For accompanists we bring in this piano.’ You can imagine what I felt.”

Pressler credits the trio’s staying together so long to their going their separate ways when they weren’t touring. “We always had that possibility of having freedom from each other. We would travel together, stay in the same hotel. We drove from concert to concert, coast to coast. That is quite something.

“You know the saying, in a chamber group you have all the disadvantages but none of the advantages of marriage, you’re so close together?”

Touring and time took a toll, however. Guilet retired in 1969 and died in 1990 at the age of 91. Greenhouse left in 1987, when he was 71, because of heart problems. In both cases, Pressler had to decide whether to continue, whether “a new group would match the level of the old.

“I knew the caliber and the quality of the trio is decided on the stage , where the chemistry, where the understanding, where the ability to react to one another is decided. In case it would not come up to the standard, in a different way, of course, I would move on.”

Isidore Cohen replaced Guilet until 1992 when Ida Kavafian joined the group. Peter Wiley took over as cellist in 1987.

“When Greenhouse left, and he left rather suddenly, Peter Wiley, who I knew from the Marlboro Music Festival [in Vermont], said he would like to tour for a year.” That one year turned into eight.

It was a personal connection that also brought Kavafian into the group. “I didn’t know her, but Wiley knew her, and life is easier if the two strings can agree on the nitty-gritty of string playing, what bowing to take, et cetera.”

Keeping his interest in music fresh is “really very easy,” Pressler said. “It starts with the love for this music. And obviously if you’re an artist who strives to get into the material, to give the message there, you know that a lifetime is not sufficient. To reach the depths of an ‘Archduke,’ you have to have a time-and-a-half of life to dispose.”

* The Beaux Arts Trio will play Monday at 8 p.m. at the John Anson Ford Amphitheatre, 2580 Cahuenga Blvd. East. Tickets: $15 and $20. (213) 466-1767. The trio also will appear with the Los Angeles Philharmonic led by Sian Edwards on Tuesday at 8:30 p.m. at Hollywood Bowl, 2301 N. Highland Ave. $1-$72. (213) 480-3232.