Explain briefly why musical instruments often appear in Cubist paintings

The Cubists chose these subjects so that we as viewers are led to concentrate on the innovations in form and structure. Georges Braque, who developed the Cubist style alongside Picasso, was a trained musician. He said "The distinctive feature of the musical instrument as an object, is that it comes alive to the touch."

Musical instruments appear often in Cubist paintings due to their uniquely geometrical designs.