Filip Topol, the leader of a Czech underground band that helped define the sound of the anti-communist revolution, has died.

Topol, who fronted Psi Vojaci, or Dog Soldiers, died in Prague, the band’s manager Romek Hanzlik said, without giving details. He was 48.

Born June 12, 1965 in Prague, Topol made his musical debut in 1978 at the summer house of then-dissident playwright Vaclav Havel, who later led the 1989 anti-communist Velvet Revolution. Topol started his three-man band the following year, and his piano, voice and dark lyrics became the band’s trademark.

Banned under communism, the band gained significant popularity in the 1990s following its collapse, with wild concerts dominated by Topol’s improvisations.

The band reunited recently, with its last concert in Amsterdam on May 25.