TAMPA — There is no warmup, no throat clearing, in Mendelssohn's Violin Concerto. The orchestra plays a measure and a half of articulated chords, and the violinist dives right into the heart of things. As Simone Porter performed it Friday night with the Florida Orchestra at the David A. Straz Jr. Center for the Performing Arts in Tampa, her resolve was unmistakable. I will tell you my story, she seemed to say. It will be a story both heroic and sad, noble and poignant. And all this, through the Romantic expressiveness of her playing, she made clear in just the first musical sentences.It was a thrilling performance. Porter displayed an emotional depth that might seem surprising in someone so young. (She is 19, and from Seattle.) None of it was forced or mannered, just a channeling of the passionate possibilities of Mendelssohn's music.Her technique, too, was something to behold. Besides the shaping of musical phrases, the violinist must navigate bravura passages of rapid fingering, double stops and exquisite ornamentation. The second movement, which is slightly slower, requires a pure and inviting tone that Porter translated into keening desire.The start of the third movement is just as arresting as the first, with violin and flute taking off together in quick and fanciful flight. It can leave you breathless. What came through, however, was not difficulty, just unfettered joy. The audience enthusiastically and unanimously leapt to its feet at the end.Shostakovich's Ninth Symphony composed the second half of the program. Written in the summer of 1945, between the Allied victory in Europe and the final capitulation of Japan, it too is full of sweeping emotion. Of course, there is a rollicking sense of victory at the beginning, full of movement and playfulness. At one point, a full battery of brass provides a martial mien. But there also is a haunting clarinet duet in the sad waltz of the second movement, along with deep and ominous strings. And after a quick and sparkling scherzo, the music returns to a mood bleak as death. It's as if the scars of war cannot be forgotten no matter the outcome. Shostakovich, who kept his artistic independence despite the strictures of Soviet control, is a master of irony. And the final movement, a mixture of merriment and danse macabre, is unsettling in its ambiguity. Different listeners hear different messages. My interpretation is that even in war's victory, the fate of man remains unresolved.It's a complex work, and guest conductor Josep Caballé Domenech elucidated it capably. Haydn's Symphony No. 96, which began the evening, was a disappointment — at least to my ear. We've had a generation of fresh interpretations of Haydn, the 18th century master of form, contrast and surprise. This was not one of them. The introduction was ponderous, not prescient; the ritards at the end of phrases were precious instead of profound. And the minuet of the third movement was one for heavy feet.