CONCERTO | Home. It was 1969, at the Paris Conservatoire, when everything changed for a pair of strong-willed, piano-playing sisters from France named Katia and Marielle Labèque. A new triple album from sisters Katia (left) and Marielle Labèque celebrates more than five decades of recording together. (Umberto Nicoletti) It was 1969, at the Paris Conservatoire, when.