With the birth of his son Paul (Paolo), he returned to the Mother and Child theme again and again.
In 1921, he painted his Cubist "Three Musicians", in which he used a group of people as a cubist subject for the first time. The three figures are characters from the Italian Commedia dell’Arte (Pierrot, Harlequin and a monk). Though created after his Cubist period, the picture came to be regarded as a masterpiece of cubism. “Those who set out to explain a picture are setting out on the wrong foot. A short time ago Gertrude Stein elatedly informed me that at last she understood what my painting Three Musicians represented. It was a still life!” wrote Picasso.