Listen to Symphony No. 1, Op. 5 "Slavonic": I. Allegro online. Symphony No. 1, Op. 5 "Slavonic": I. Allegro is an Instrumental language song and is sung by Gennady Rozhdestvensky, Bolshoi Theatre Orchestra and USSR Ministry of Culture Symphony Orchestra. Symphony No. 1, Op. 5 "Slavonic": I. Allegro, from the album Glazunov: Complete Symphonies, was released in the year 2010. The duration of the song is 10:55. Download Instrumental songs online from JioSaavn.