"A symphony of sound" is essentialy a one long loose improvisation during a practice session at Andy Warhol's Factory; shot in January 1966, it shows the Velvet Underground & Nico rehearsing for what was probably their opening at the Film-Makers' Cinemateque basesement theater. Great deal of wild camera work and psychedelic zooming. The child at Nico's feet is her 3-year old son Ari, who's father was French actor Alain Delon.