The Petersburgian composer and musicologist Igor Vorobyov (born in 1965) is the author оf music- scenic, chamber, choral and vocal compositions. Such works as “Russian Avantgarde and Alexander Mosolov's Creativity of 1920–30” belong to him, so as the collection of poems “Nocturne 33”. Sonata for viola and piano was composed in 2001. There are some special features of soloing viola, i. e. the muffled pastel timbre, inclination to pensive melodious sphere, but not to mere virtuosity. These peculiarities of viola left traces on actually the whole tradition of viola music. The Sonata by Igor Vorobyov exposes the traits of this tradition. The inner tension is perceived by the listeners the more candid, the more complicated its way to open expression is. The unity of this way connects both of the Sonata's movements, for the second movement continues the process of this concealed emotional revelation, though being in the other hypostasis. Thus the lyrical sphere of the second movement seems quite delusive from this point. The Sonata for viola by Igor Vorobyov was fitstly performed in the Maly Hall of St Petersburg Philharmonic Society by V. Stopichev (viola) and N. Lee (piano) on March 21, 2002.