I find it really weird when people just run with this misconception that western literate music somehow started with Bach, as if what people were playing before was something different and not really music. One can clearly hear continuity between late Renaissance and early Baroque style (17th c.) and even how the secular music of the later Middle Ages (the sources of which are sadly a bit too obscure, hence why it's not often performed even as 'early' music) was carried over into the early Renaissance. Bach's style was highly individual, blending highly developed structures and forms of earlier Renaissance music with the fully developed tonality of the later Baroque and the earliest elements of 18th c. ("galant, classical") style.