Mark Sforzini is best-known for leading the St. Petersburg Opera Company, where his precise musicianship and ebullient personality have taken the company to great heights. But he’s also Maestro of the Tampa Bay Symphony, who bill themselves as “a volunteer company with a professional sound,” and with Sforzini at the podium you can bet that’s an accurate description. In their concerts tonight at the Palladium on on May 5 at the Straz, they’re taking on Sibelius’s Symphony No. 2, aka Sibelius’s Mighty Second, as well as playing works by artists  who have come out on top in composition and young artist competitions. 4/30, 8 p.m., The Palladium; 5/5, 2:30 p.m., Ferguson Hall at the Straz.