A little-known aspect of Gaetano Valeri’s musical production, and one still to be studied, is represented by his Sinfonie, the parts of which are extant in manuscript in the Biblioteca Capitolare of Padua (cat. nrs. 59. 21, 28-33) and in the Biblioteca Civica of Lugo di Romagna (C 13). Gaetano Valeri uses the term “sinfonia” to indicate his instrumental compositions (for strings and two pairs of winds) written in a single movement, or occasionally in two movements (Allegro and Largo) with a repetition of the first, utilizing the form which he most favored in his keyboard sonatas. The option of a single movement was characteristic of composers from the Veneto (the most significant representative being B. Galuppi), and it continued to be a favorite form of Paduan composers even at the end of the eighteenth century.
In the case of the bipartite works, Valeri juxtaposes episodes contrasting in both character and tempo, following the example of B. Marcello and, again, Galuppi. The repetition of the fast first movement, on the other hand, reflects a formal structure employed by P. Anfossi in the “da capo” ouverture. Like the sonatas, Valeri’s Sinfonie commonly present a division into two parts, recalling the dance forms of the baroque suite. The subdivision is unrelated to the thematic organization since each part is in turn divided into two sections within which the thematic material is distributed, preferably following a pattern of ABAB.
The themes are played twice, separated by secondary elements of a virtuosic character. The treatment does not yet foresee the classical sonata form of exposition-development-recapitulation; instead, we still find a series of motifs of contrasting character linked by melodic passages, following the teachings of G.B. Sammartini. Although not unaware of the innovations of classicism, Gaetano Valeri apparently chose to hang on to stylistic elements typical of the stile galante, preferring the simplification of compositional form which favors the relationship between melody and accompaniment.