concertato
Noun
Meaning
(music) An early Baroque genre or style of music in which groups of instruments or voices share a melody, usually in alternation, and almost always over a basso continuo.
A piece of music in this style.
Source: en.wiktionary.orgExamples
Most of Allegri's published music, especially the instrumental music, is in the progressive early Baroque concertato style.
The term "a cappella" was originally intended to differentiate between Renaissance polyphony and Baroque concertato style.