50. Quartetto in Re

Magri 1974 and Magri 1999 give detailed descriptions of the musical construction.
A string quartet “per Bazzini” is mentioned in two published letters of Puccini to his mother.Note: *Marchetti 1973, No. 5 (9 March 1881), and Epistolario 1982 No. 2 (in this respect un-datable, as it is obviously comprised of several different letters).  It must remain open whether it is this quartet movement — which, in that case, would already date from March 1881. However, the catalogue of Sotheby’s auction of 16/17 May 1991, No. 382, mentions the title page of a “Quartetto in Re”, signed “Giacomo Puccini 1882”.
50 probably is the first movement of that quartet, with the Adagio (31), the Scherzo (34), the Trio (52), and the Scherzo per Archi (56) comprising the integral composition.