While not much is known about Giovanni's early life, he probably studied with his uncle, the composer Andrea Gabrieli, who was employed at St Mark's Basilica from the 1560s until his death in 1585.
Some of the most renowned singers and instrumentalists in Italy performed there and a vivid description of its musical activity survives in the travel memoirs of the English writer Thomas Coryat.
San Marco had a long tradition of musical excellence and Gabrieli's work there made him one of the most noted composers in Europe.
Evidently, he also instructed his new pupils to study the madrigals being written in Italy, so not only did they carry back the grand Venetian polychoral style to their home countries, but also the more intimate style of madrigals; Heinrich Schütz and others helped transport the transitional early Baroque music north to Germany, a trend that decisively affected subsequent music history.
Gabrieli was increasingly ill after about 1606, at which time church authorities began to appoint deputies to take over duties he could no longer perform.
[5] Among the innovations credited to him – and while he was not always the first to use them, he was the most famous of his period to do so – were dynamics; specifically notated instrumentation (as in the famous Sonata pian' e forte); and massive forces arrayed in multiple, spatially separated groups, an idea which was to be the genesis of the Baroque concertato style, and which spread quickly to northern Europe, both by the report of visitors to Venice and by Gabrieli's students, who included Hans Leo Hassler and Heinrich Schütz.
[6][7] Like composers before and after him, he would use the unusual layout of the San Marco church, with its two choir lofts facing each other, to create striking spatial effects.
The motets published in Giovanni's 1597 Sacrae Symphoniae seem to move away from this technique of close antiphony towards a model in which musical material is not simply echoed, but developed by successive choral entries.
In particular, one of his best-known pieces, In Ecclesiis, is a showcase of such polychoral techniques, making use of four separate groups of instrumental and singing performers, underpinned by the omnipresent organ and continuo.