In the classical tradition of soloist-as-conductor, violin virtuoso Nikolaj Znaider performs as concerto soloist while leading the Cleveland Orchestra, starting tonight’s program off with Mozart's Violin Concerto No. 3, a cheerful and light-hearted concerto bursting with such life that even the somber, minor-key moments sing with a sense of reassuring emotions. The equally joyous but much more active and grandiose Symphony No. 4 ("Italian") by Felix Mendelssohn follows. To close the evening, Znaider leads Elgar's famous Enigma Variations, a musical character-study of the composer's friends and family. The program takes place tonight at 7:30 at Severance Hall. You can also see the concert tomorrow at 11 a.m. (this performance will only include the Mozart and Elgar works) and Saturday at 8 p.m. Tickets run from $31 to $149. (Stoops)