Several of Sebastiano's letters during the summer and autumn of 1533 refer to an edition of some madrigals by Michelangelo, which had been set to music by Bartolommeo Tromboncino, Giacomo Archadelt, and Costanzo Festa.

In the centre are three kneeling figures: on one side St. Catherine (or perhaps Caterina Sforza in the character of St. Catherine, for the head looks like a portrait); on the other an elderly woman, Ginevra Tiepolo, widow of Giovanni Sforza, last prince of Pesaro; between them the little Costanzo Sforza, looking up with a charming devout expression.

[Footnote 3: Lanzi calls this child Costanzo II., prince of Pesaro.

Tradition connects the painting of this altar-piece with an event of the year 1504, the death of the young Matteo Costanzo, whose family, so it is said, commissioned Giorgione to paint a memorial altar-piece, and decorate the family chapel at Castelfranco with frescoes.