Petrov was a pianist and composer of classical and popular music. He stemmed from the family of a Russian emigrant of aristocratic origin (family Repnin), a family doctor, resident in Prague-Žižkov. At first, he attended a Russian high school in Prague district Pankrác, during which time he was preparing for his future piano and composition studies at the Music Faculty of the Academy of Performing Arts (AMU), taking piano lessons with Berta Kabeláčová and music theory and composition lessons with Miloslav Kabeláč. At the Academy he was Jaroslav Řídký's student from 1952 to 1956. His graduation composition was the symphonic poem "The Vítkov Hill" (Vítkov – the place of the decisive battle in 1420 near Prague). He worked in the Prague Municipal Education Centre, where he was in charge of the Folk Entertainment department. In the 1960s he founded the People's Conservatory specialising in dance-music and jazz (now Jaroslav Ježek Conservatory and College), and became its first director.