As a singer and songwriter, he pushed the boundaries of punk and art-rock, producing a half century of music, writings and performances and always upending expectations.

David Thomas, who fronted the boundary-pushing rock band Pere Ubu from the late 1970s forward, died Wednesday at age 71. The news was announced on the group’s Facebook page, where the cause of death was only given as the result of “a long illness.”

David Thomas, who helped shape the sound of new wave and post-punk music as the howling, playfully anarchic lead singer and lyricist of Pere Ubu, died April 23 at a hospital in the English city of Brighton and Hove.