TAMPA — The kids are in charge. And they surely know how to handle their elders.Joshua Weilerstein, a conductor so trim and youthful he could be mistaken for a teenager (he's actually 27), adroitly led the Florida Orchestra through a wide-ranging and deeply satisfying program at Carol Morsani Hall on Friday night.And Karen Gomyo, a solo violinist only 6 years older, demonstrated with aplomb how technical brilliance need not be flashy when it serves purity of tone and the expressive elegance of a musical phrase. In Mozart, that's harder than it looks. Gomyo's telling of his Fifth Violin Concerto was eloquent and sublime. I might go buy another ticket just to hear it again.Weilerstein, making his second guest appearance with the orchestra this season, fleshed out the youth-and-age narrative during his insightful (if somewhat rushed) opening remarks.He described composer Thomas Ades, now in his 40s, as obsessed with the musical past, particularly the harpsichord music of Francois Couperin, born three centuries earlier. Wolfgang Amadeus Mozart was famously a prodigy — he wrote all five of his violin concertos in one year, when he was 17. And Brahms, after an unusually delayed adolescence, seemed old even before he was. Brahms might not have easily gotten along with people, Weilerstein said, but his music expresses a deep humanity.Indeed, each piece Friday had something unique to offer.Three Studies from Couperin, composed by Ades in 2006, is a careful rendition of notes that Couperin actually wrote, but processed and colored in an entirely new way. There is a muted elegance to the first part, subtitled The Amusements, with unusual sounds coming from alto and bass flutes, and even a marimba. The second part, whose French title can be translated as Jugglers Tricks or Sleight of Hand, playfully juxtaposes fragments of melody; the result sounds at times like Prokofiev. The Troubled Soul, which closes the set, is more somber; it is a stately lament, a combination of tensions raised and resolved, decorated with light ornaments. Under Weilerstein's sensitive direction, it managed to be both gossamer and weighty in the right portions.The light texture of Mozart might sound simple, but in his music there is also no place to hide. To achieve personality, a musician must pay careful attention to the shape of each note and phrase. To do this while still sounding light on your feet is quite a thing, and the orchestra gave one of the most natural and transparent performances I have heard in a while.Weilerstein didn't over-conduct, his left hand and the baton in his right simply coaxing the players along, with judicious gestures of time and intent. The music itself took the lead, along with Gomyo's brilliant playing. Her trills and ornaments were not just decorations; they were integral parts of the rhythm and melody. Her cadenza at the end of the second movement had a beautiful sense of suspension that made me hold my breath. At the end, she received an enthusiastic and unanimous standing ovation, richly deserved.Then there is Brahms. His fourth and final symphony is a formidable piece of work, with grand themes, stunning harmonic evolutions and great issues to be wrestled with. Friday's performance breathed clearly and well, its sweeping melodies balanced with staccato punctuations from various parts of the orchestra. To watch Weilerstein conduct is a thrill; he dances, he jumps; he embodies the changing moods in his body and face.But this is a big piece. None of that would matter if he didn't also bring significant commitment, intelligent control and resolve. And he did.