The piano was a constant presence throughout Berio’s life, from the charming early Petite Suite to the compelling drama of the Piano Sonata, one of his last works. Berio’s profound exploration of this instrument’s timbres and possibilities is further in evidence in the Webern-like concision of Cinque variazioni and the famously virtuoso Sequenza. The obsessiveness of Rounds and the deeply personal Six Encores complete a recording that marks the 20th anniversary of Berio’s death in 2023.