You see them at every concert, moving purposefully around the stage, navigating around — and even on — the conductor's podium. They're there before the music starts, between compositions, at intermission, and — if you linger before exiting the hall-again after the performance. They're dressed in full formal concert regalia, like the orchestra members, but they don't play. Who are these people?

They're the DSO's orchestra librarians, fulfilling a crucial role that adds new dimension to the phrase "behind the scenes."

According to DSO Librarian Karen Schnackenberg, "The number one priority: getting the right music in the right place at the right time. It all grows from there."

Presenting concerts involves considerably more than rehearsals. The orchestra library and its staff are essential to operations. "It's all about acquisition of music, whether by purchase, rental, or borrowing; preparation — organizing the music for performances, actual physical stage work during the concert, distributing and gathering music, setting up before and during the performance," says Schnackenberg. "The final part of that process is collecting the music, reshelving it, or sending it back.

"That's just for the concerts," she continues. "Then there's all the adjunct activity like cataloguing, maintaining the collection, repairing as needed. Of course, that entails ordering music."

In concert, the conductor works from a full score that shows every instrumental part. All the woodwind, brass, and percussion musicians play from individual parts; each string player shares music with a stand partner. That means approximately 65 parts for each composition. Pops concerts get exceedingly complicated for the librarians, because there are so many separate pieces on each program. In any given year, the DSO librarians handle more than 20,000 pieces of music.

The orchestra library, which is housed on the main floor of the Meyerson along the same corridor as the music director's office, is a bustling and crowded place. Schnackenberg and Associate Librarian Mark Wilson, who boast 33 years of DSO experience between them, spearhead library operations, supervising a skilled group of part-time assistants on an as-needed basis. Their daily activities include editing, proofreading, correcting errors in the printed music, and matching up rehearsal cues so that the players know precisely where to start when the conductor resumes after stopping to fix something.

Orchestra librarianship demands a high level of musical literacy. Schnackenberg is a violinist with two degrees in music; Wilson holds a degree in music education and plays both piano and double bass. She started marking parts in junior-high orchestra and became increasingly involved in the field as a graduate student at the University of Oklahoma. Wilson taught school briefly, then worked for seven years in the rental library of Boosey & Hawkes, a major music publisher. His experience at that end of the business has been invaluable, especially since Boosey remains one of the DSO's principal rental houses.

The library also owns a considerable amount of music. It can cost several hundred dollars to rent one set of parts for a weekend of performances of a standard work, as opposed to about $500 to purchase. "You pay for it in two usages," explains Schnackenberg. "It's best to acquire as much of the public domain music as we can. Of course, music under copyright must still be rented."

Music librarians' work is very detail-oriented. Each part must be marked and corrected for articulations as small as staccato marks, changed notes, dynamics, a wrong rehearsal cue, a missing key change. Librarians also mark bowings, which is the reason that all the string players in a section bow the same way. (It also helps with page turns.)

"A musician is a musician," declares Schnackenberg. "Mark and I are both players. You never divorce that from your work. Everything we do comes from that knowledge. We have to be able to transpose, to understand the ranges of each instrument, put in an insert." Wilson adds: "And we have to be able to do it in 15 minutes, if necessary."

Because American orchestras have less rehearsal time than European ones, Schnackenberg and Wilson have been forced to become what she calls "über-efficient — so the orchestra doesn't waste any rehearsal time fixing bowings or correcting errors."

Both of them are active in MOLA, the Major Orchestra Library Association, and agree that it is a great time to be in the orchestra librarianship field. "What other professions do you know where they're still using paper, pencil, and erasers?" asks Schnackenberg with a laugh. Yet new technology is changing their world as well. Wilson says, "We have a fun little toy called a DocSend EFI manipulator. We use it to scan in old, dog-eared parts to appear on a screen, then clean them up. When we print it out, it's enlarged, on beautiful white paper without yellowing or creases. That lessens the amount of physical labor."

Asked what is the most rewarding aspect of their work, Schnackenberg responds without hesitation, "When we hear a great performance by the DSO." Wilson adds, "And knowing that we had a part in it, that they couldn't have done it without us."