1600-1750
‘Baroque’ probably comes from a Portuguese word, barocco, meaning an irregularly-shaped pearl or piece of jewellery. It was first used in connection with the highly ornamented style of architecture and art of the 17th century. Later on, musicians came to use the word ‘Baroque’ to describe the period of musical history from the birth of opera and oratorio to the death of J .S. Bach.
It was during the 17th century that the system of modes finally crumbled away. Composers had grown accustomed to sharpening a note here and flattening a note there, with the result that modes lost their individual characters and came to sound like two modes only - the Ionian and Aeolian. From these grew the major-minor key system upon which harmony was based for the next two centuries.
The 17th century also saw the invention of several new forms and designs, including opera, oratorio, fugue, the suite, sonata and concerto.
The violin family replaced the viols. And the orchestra gradually started to take shape, with a strong section of strings as its foundation - though the other sections were as yet not standardised.
All these experiments and changes prepared the musical ground for the two giants of later Baroque music: Bach and Handel.