The standard texture of Baroque music is polyphonic (or contrapuntal). Even many Baroque pieces that consist of just melody and bass count as contrapuntal because of the independent melodic quality of the bass. And large-scale pieces spin a web of contrapuntal lines filling every nook and cranny of musical space-time. While cellos, basses, bassoons, and organ pedals play the lowest line, the other stringed instruments stake out their places in the middle, with oboes and flutes above them and the trumpets piercing their way up into the very highest reaches of the sound universe. The density achieved in this way is doubly impressive because the sounds feel alive — alive because they are all in motion, because they are all parts of moving contrapuntal lines.

Again, some exceptions should be noted to the standard polyphonic texture of Baroque music. Such are the homophonic orchestra sections (the ritornellos) in the concerto, Bach’s Prelude in C Major from The Well-Tempered Clavier (see page 129), and his highly expressive harmonizations of old German hymns, as in his Cantata No. 4 (see page 147). But it is no accident that these textures appear within pieces that feature polyphony elsewhere. The ritornello in Bach’s Brandenburg Concerto No. 5 alternates with polyphony played by the solo flute, violin, and harpsichord (see page 123). The harmonized hymn in his Cantata No. 4 comes at the very end, where it has the effect of calming or settling the complex polyphony of all the preceding music. And the Prelude is paired with a fugue, the high point of imitative polyphonic art in the Baroque era.