The night before the first day of her first real job out of college, Kaitlyn Resler wasn’t too worried about what she’d wear or how she’d remember her many co-workers’ names. She’s normally not the type to dwell on horrifying possibilities and over-analysis.

Then she thought about her knee.

French horn players, like Resler, have varied opinions on whether it's best to play "on the knee," with the bell resting on their laps as she does, or "off the knee." She realized, less than 24 hours before her first rehearsal as a full-time Florida Orchestra musician, that principal horn player David Smith was an off the knee guy.

Did that mean she should also play off the knee? The question was now freaking her out.

Luckily, she had someone she could turn to. Carolyn Wahl, her horn instructor from fourth grade through high school told her, via text, to remember what got her the job over 57 other horn players who participated in blind auditions. Do what's comfortable for you.

The next morning, Jan. 2, Resler played on the knee, and the former teacher and student officially became co-workers. Resler, who is 23 and the newest member of the orchestra, now sits directly to the left of Wahl, 67, who has been a horn player with TFO since the 1974 season, the longest run of any current musician.

It's a rare situation, said the orchestra's spokeswoman, Kelly Smith. She'd asked around, and nobody could remember a former student and teacher playing together, let alone the newest and longest-running musicians in the orchestra being seated side-by-side. To add another unlikely layer, Resler is a Tampa Bay native, raised in Clearwater, in an orchestra where almost all the musicians hail from elsewhere around the globe.

For her first day, Resler had picked an outfit professional enough — a striped, long-sleeve shirt, pants and short boots — but she was not so formal as to be out of place with the flautist in a screen-print T-shirt and jeans who sat in front of her, or the boss, guest conductor Thomas Wilkins, who wore a voluminous pair of khakis and an untucked denim shirt.

Wahl wore a zippered jacket with an intricate red pattern that seemed fancy enough for a performance night, except that it wasn't all black.

At the Mahaffey Theater, they rehearsed Dvorak’s Symphony No. 7 and William Grant Still’s Symphony No. 1. The conductor laughed and joked a little when he stopped the orchestra to make tweaks, but Resler’s face remained an intense mask of concentration until it was over. Then she removed the plastic-framed glasses she wears while playing, smiled and looked like a different person. Wahl removed her own glasses, placed them in a case, and put on a different pair. The veteran musician looked very much the same off stage as on; calm and nonchalant.

In an empty dressing room, Wahl thought back to her own first day 45 years ago. Conductor Irwin Hoffman had filled her with respect and terror.

"He was volatile and not easy on people. I kind of learned early on how to stay out of the way of that."

Resler had just made it through her first rehearsal without the conductor, who seemed quite nice, making any direct mention of the horn section. She regarded this as a success.

Could Wahl remember her first impression of a 9-year-old Kaitlyn?

"I can recognize talent."

On this, the proof stands. Principal horn in the San Francisco Opera and Ballet. Principal horn at the Washington National Opera at the Kennedy Center. Principal horn in the Tokyo Symphony. Principal trumpet at the Orquesta Sinfónica de Yucatán. These are her former students.

They don’t all work out. Just before Resler came to her, Wahl had two very gifted horn players “flame out” in high school. With Resler, she was incredibly cautious. She realized “it has to stay fun.” She tells students now, “it doesn’t matter to me what you do with your life. Just be the best you can be with the horn, so that you have this for yourself.”

"I never felt any pressure," Resler said. "Over time, she became a second mom to me."

Wahl has in her four decades seen downturns in the arts and taken pay cuts and watched as regional orchestras in New Orleans and Orlando and elsewhere went out of business.

She has seen the Florida Orchestra survive and grow again. Resler did not replace anyone. She won the first position added to the orchestra since the 2011-2012 season, and brings the total number of full-time TFO musicians to 67. Last year, the orchestra agreed to increase its base pay 12 percent to $40,040.

Wahl’s best friend, Justine LeBaron, was once the principal horn player, and they sat next to each other in the orchestra for many years. When LeBaron became deathly ill, she sold her horn to Resler, then in high school and unable to afford a professional instrument, on a payment plan. Resler still owns the horn, mutes and horn stand that reads “LeBaron.”

Wahl has long thought it would be nice if one of her former students replaced her someday, but she never thought she'd play alongside one of them.

Asked what's driving her at the start of her career, Resler, who will return to the Juilliard School to wrap up her master's degree in the orchestra's offseason, immediately said, "Sharing music with as many people as possible in the community and helping bust the stereotype that the orchestra is only for highly educated, upper-class people." Spoken like a young idealist.

Asked what was driving her after 45 years, Wahl took a long pause. It seemed she hadn't thought about it in a long time.

"I just love playing the horn," she said. "When I don't love it anymore, I'll stop."

IF YOU GO

The Florida Orchestra with Cuban jazz pianist Aldo López-Gavilán perform George Gershwin's Rhapsody in Blue

$18 - $48. 8 p.m. Friday at the David A. Straz Jr. Center for the Performing Arts in Tampa, 8 p.m. Saturday at Mahaffey Theater in St. Petersburg and 7:30 p.m. Sunday at Ruth Eckerd Hall in Clearwater. (727) 892-3337. floridaorchestra.org.

Contact Christopher Spata at cspata@tampabay.com or follow @SpataTimes on Twitter.