Mario de Pietro was a mandolin and banjo player who was very popular in the 1930 in the UK. Several movies have been preserved in the archives of British Pathe. The videos are also available on youtube.
JOAN REVEL AND MARIO DE PIETRO
Schön Rosmarin (Kreidler) /Lollipops (8.9.1930)
Playlist MARIO DE PIETRO
Additional information
The mandolin method by Mario de Pietro – The First Step how to play the Mandoline – is available on my website: