The violin player looked distressed and about to give up in disgust from having to share a mike with her. At one point he looks around desperately to see if anyone else is sympathetic to his plight, but they're all either too stoned or oblivious out of deference to Lennon. If Lennon insisted on letting her sing, I'd quit his band, too! The scenes of people clapping enthusiastically at the end must have been edited from another performance, unless they were simply celebrating that she finally ended the torture.