Career
All that is positively known about him is what is found in Dante"s work and it has been impossible to identify him with absolute certainty with any of the Casellas named in contemporary documents. To whatever is said of him in Dante"s work one can add (with some degree of probability) information furnished by the earliest commentators of the Divine Comedy: Pietro di Dante, Benvenuto da Imola, Buti and Landino give him as being born in Florence, while an anonymous early commentary of the Divine Comedy gives him as being born in Pistoia. Mentions of this Casella in documents probably include a mention (Casella d sonum, ie "Casella set to music") in Codex Vaticano 3214 that he set to music a madrigal by Lemmo da Pistoia, and a mention of him in a sonnet by Niccolò de" Rossi.