Bach, Johann SebastianBach, Jo‧hann Se‧bas‧ti‧an /bɑːk, bɑːx, ˈjəʊhæn səˈbæstiən $ ˈjəʊhɑːn səˈbæstʃən/(1685–1750) a German musician, one of the most famous and admired European composers. He is especially well known for his organ music and his religious choral music (=for musicians and singers), which is typical of the baroque style.