Complex sentence: The Palau became an emblematic theatre for Catalan singers of the Nova Cançó (New Song, or Catalan popular song from 1960s): singing at the Palau was a kind of consecration for a singer.
Split into simpler sentences: The Palau became an emblematic theater for Catalan singers of the Nova Cançó (New Song, or Catalan popular song from 1960s). Singing at the Palau was a kind of consecration for a singer.