Francesc Valls (Barcelona 1665/1671 - 2 February 1747) was a Catalan composer, theorist and mestre de capella. Among his most known works are the mass Missa Scala Aretina and tract Mapa Armónico Práctico.
In 1696 Francesc Valls left the Church of Santa Maria del Mar, Barcelona, and took up the post of Mestre de capella at Barcelona Cathedral. He wrote 10 masses, 17 psalm settings, 30 motets, several other sacred items and 141 secular compositions. Many of these are manuscripts lodged in the Biblioteca de Catalunya in Barcelona.
The Missa Scala Aretina, so called because it uses a scale-based cantus firmus (prominently audible in the Kyrie), caused a major musical controversy between 1715 and 1720, initiated by a pamphlet against Valls by the organist and theatre composer Joaquín Martínez de la Roca. Pro and anti groups were roughly equal, the famous composer Alessandro Scarlatti had given an opinion, mildly opposed to Valls' ideas. In the Qui tollis at bar 120 (López-Calo edition) the second soprano enters on an unprepared 9th chord causing a gratuitous semitonal dissonance with a b flat, a, f, d and low g sounding simultaneously on the words miserere nobis. The unpreparedness of the entry rather than the discord is the problem. It is doubtful whether such a chord would have raised eyebrows in England where the dissonant music of Henry Purcell or William Lawes had been admired at court and church. Many of Valls' other works, however, use harmony which was highly unconventional at the time (see below).