The detection of acoustic vibrations is one of the main applications of sensors which are based on piezoelectric polymers. Provided with methods to prepare and characterize such thin, minimally invasive film-sensors, many phenomena of the physics of musical instruments can be newly investigated and reassessed. In combination with conventional sound measurements available in the acoustic laboratory, the relations between structure-borne and airborne sound can be captured. This provides new insight into the mechanisms that are involved in the sound production of musical instruments. Studies that were previously conducted in the group partially by means of polymer-film sensors comprise the oscillations of organ-pipe bodies, the influence of ribs on piano soundboards and the vibrations of violin bridges. Moreover, the synchronization of organ pipes via sound coupling has been investigated. Organ pipes and bowed-string instruments remain a current research topic.