Complex sentence: As De Larrocha aged, she began to play a different style of music; more Mozart and Beethoven were featured in her recitals and she became a regular guest at the Lincoln Center for the Performing Arts's Mostly Mozart Festival in New York.
Split into simpler sentences: As De Larrocha aged, she began to play a different style of music. More Mozart and Beethoven were featured on her recitals and she became a regular guest at Lincoln Center for the Performing Arts's Mostly Mozart Festival in New York.