Audiences may not notice the

Philadelphia Orchestra

's new principal tuba player,

Carol Jantsch

, hidden as she is behind the thicket of string and wind players.

But her hiring two years ago was a historic event, though she was one of the few who wasn't surprised.

Jantsch, who turns 23 on March 8 and is now in the midst of her second season, is simply an extraordinary musician, one whose gifts will be on display Sunday in a guest-artist recital at Temple University's Rock Hall.

Rather than marvel at her age, she'd prefer that attention be paid to the solid contributions and magnificent singing tone she makes on an instrument most people think just goes oompah.

During her final auditions here two years ago, she played as a substitute for six weeks. One of those concerts was the Bruckner Seventh Symphony under the baton of Simon Rattle, and her hearty playing made it obvious that she was the perfect choice from among 194 candidates.

The instrument's size and clumsiness prevent many girls from taking it up in school bands. Jantsch herself started on the piano at 6, then switched to the euphonium, a smaller version of the tuba, three years later.

In seventh grade, she became a tubist whose amazing skill was swiftly apparent. She played difficult sonatas from memory and won awards in Germany, Hungary and her native Michigan while studying at the University of Michigan and the Interlochen Arts Academy.

It'll probably be a few years before she plays a concerto with the Philadelphia Orchestra. Meanwhile, this weekend she'll play one written for her predecessor, Paul Krzywicki, by his brother, Temple professor and composer Jan Krzywicki (also conductor of the Network for New Music ensemble).

It was premiered by the Temple University Symphony Orchestra under Luis Biava in 1997.

"She is a beautiful, very facile, accurate player," said composer Krzywicki, "with an uppermost register that retains a very full sound."

Jantsch's partner in the concerto, playing the keyboard reduction of the orchestral part, is the superb pianist Susan Nowicki, who said, "I'm so impressed with Carol, a brilliant player and musician."

During our discussion, Jantsch revealed that she doesn't lug her instrument home to her apartment, practicing only at the hall out of consideration for her neighbors.

"I never really played much orchestral repertoire in college," said Jantsch. She was a member of the college band for eight semesters and orchestra for only two. "We had a wonderful band director, the parts were better, and there was more to do. It was a great place to do stuff for the first time.

"I was a sort of Chicago Symphony kind of kid and didn't know a lot about Philadelphia. Gene Pokorny, the Chicago's tuba player, was an inspiration - an incredible, amazing sound, the biggest, fattest, clearer sound, so beautiful.

"The usual comments were for me to play a little louder and expand my volume, because I never was a super-aggressive player. It's hard in pieces when you rest for a long time and then come in loud. That's always a struggle the first two weeks of the season, and though you can practice playing cold, you need to do it on the job."

Jantsch is an enthusiastic, national-level Ultimate Frisbee player. Highly competitive devotees play locally in a field house during the winter and in Fairmount Park the rest of the year.

Her taste in music is eclectic, a mix of chamber music, jazz, hip-hop, Latin and funk, as well as classical works.

Besides Krzywicki's Tuba Concerto, Jantsch will play some unfamiliar pieces designed to demonstrate the considerable tonal range of her instrument. Her bill includes Penderecki's Capriccio, Three Miniatures by Anthony Plog, "Reverie and Pursuit" by Chia-Yu Hsu and Eric Ewazen's Trio for tuba, trombone and piano, with her boyfriend (and recent Curtis Institute graduate) David Murray as trombonist.

We asked if it was difficult waiting through long symphonies where the tuba only plays in the finale.

Jantsch replied: "There are worse things to do as a job than to just listen to the Philadelphia Orchestra." *

Send e-mail to dinardt@phillynews.com.

Rock Hall, Broad Street and Cecil B. Moore Avenue, 3 p.m. Sunday, free, 215-204-7600, www.temple.edu/boyer.