Klusák was born to a Czech Jewish family, who owned a farm in Prosek, Prague.

After he graduated from the gymnasium, he pursued his studies at the Prague Music Academy as a pupil of Jaroslav Řídký and Pavel Bořkovec (in 1953-57[1]).

However, after the Warsaw Pact invasion of Czechoslovakia in August 1968, Klusák was condemned as a "politically undesirable" person (he composed music for prohibited films).

[2] Following the Velvet Revolution in 1989, he began to participate in public life again, and worked as a member and director of various cultural institutions in the Czech Republic.

[3] Since the 1960s he occasionally acted in films, such as A Report on the Party and the Guests (1966) or Valerie and Her Week of Wonder (1970).