From Albinoni to Zilcher, from Max Zach to David Amado, the living musical history of our Saint Louis Symphony Orchestra resides in an unassuming, rectangular room not much larger than a library bookmobile.

Rows of music are housed on shelves that fold up like an accordion to make the most of cramped quarters. Those scores of scores with millions of notes rest in the care of two individuals: librarian John Tafoya and associate librarian Elsbeth Brugger. And, yes, they're musicians, too.

If you're reading this while in Powell Symphony Hall, look at the stage. In front of the red chairs are stands with sheets containing music that our players will bring to life. If you're here a tad early, you might spot one or two individuals placing sheet music on those stands. That would be John and Elsbeth. Without their expertise, the music we experience wouldn't be as pleasant.

"One thing we do is anticipate questions or problems that our musicians face," says Tafoya in an interview inside Powell Hall's basement library.

Like Radar O'Reilly on M*A*S*H?

"Exactly," he says with a smile. Preparation is the key.

"Our job is to make the musician's job easier by providing the best possible orchestra parts available," says Tafoya, who has worked in the library since August 1976 and has performed on occasion with the Orchestra as a trombonist.

"Working with our world-class musicians and knowing that our work in the library facilitates great performances is enormously rewarding," adds Brugger, an employee since 1983 and a former violinist and violist. "Of course, hearing the Orchestra rehearse and perform while I'm working is wonderful."

Well in advance of rehearsals, the librarians confer with the conductors to make sure they obtain the right score from a publisher. Surprisingly, changes are sometimes appended to younger pieces and even to old standbys like a Beethoven symphony.

"New editions come about as a result of a scholar's research," Tafoya explains. "A conductor may decide to use the new edition while others might stay with an earlier one."

"It's up to us to make sure we provide the conductor with the edition he or she wants to use," Brugger says. "Then we get the parts ready for the musicians' folders."

Some scores present a composer's idea but lack details that a musician needs in order to play a piece successfully. The librarians help clear up ambiguity by making sure the notations in the parts are appropriate for the players.

This can be a time-consuming process, but one that must be completed in advance since many musicians like to pick up their parts well before rehearsals begin.

Once the music is placed on the musicians' stands, the librarians attend rehearsals just in case there are any problems. After the performances the music is returned to the library. On one Monday this fall, the scores for Shostakovich's Symphony No. 11, played the preceding weekend, were filed for another time. Meanwhile, the music for the next two concerts was already in musicians' folders.

Of course, challenges inevitably arise despite the time-tested regimen. One season Leonard Slatkin included Mahler's Symphony No. 10, which was unfinished when the composer died. The version the Orchestra performed was completed by Remo Mazzetti.

"At a pre-rehearsal that was scheduled well in advance of full-scale practices, which Leonard had suggested, given the piece's complexity, we realized the scores weren't copied properly," recalls Tafoya. "They had been poorly copied by hand, and there were mistakes in the conductor's score as well as in some of the orchestral parts. We proofread every part and made countless corrections prior to the rehearsals. The result was a splendid rendition that was recorded by Slatkin and the Orchestra. Fortunately, not every work requires such in-depth preparation."

The Orchestra musicians appreciate the care and attention to the music, and often take part in the process‹ particularly the principal string players.

"Typically, we start a bowing review process early, sometimes even in summer to get the parts ready before the first reading," says Concertmaster David Halen. "The rest happens during and between rehearsals. The incredible amount of detailed editing makes it possible for us to play together exactly. Having irreplaceable experts like John and Elsbeth with us for so many years has been crucial to the artistic success and overall quality of each performance."