Titles read: "MARIO LORENZI - PIC MUSICAL".
London, probably Pathe Studio.
Various shots of harpist Mario Lorenzi playing The Waltz of the Flowers from The Nutcracker by Tchaikovsky. C/U of his foot on the pedals at the base of the harp. Dramatic M/Ss show Mario playing, lit from the side so that his shadow is projected onto the wall behind.
Note: also known as Mario 'Harp' Lorenzi.