Generally speaking, the Baroque period is when the orchestra was born, opera kicked off in a big way and the concerto gave soloists the chance to properly show off. From the period's beginnings in the early 1600s to when the Classical period style began to take over in the mid 1700s, the sound of the Baroque period remained distinct - ordered, ornate and increasingly emotive as the period went on.
The Baroque sound In a practical sense, there are some truly defining characteristics in the Baroque period that mark it out from what came before or after. You can expect to hear a lot of harpsichord, for one, but more generally, the main progression that came as the Renaissance period turned into Baroque is the emergence of more modern harmony. By harmony, we mean the combination of more than one note at the same time, and baroque composers like Bach, Handel and Vivaldi just made it that bit more accessible.
Baroque instruments Though many instrumental developments were made in the baroque period, there's one rather large, keyboard-shaped shadow cast over all of them - by the harpsichord. You'll hear its distinctive plucked sound all over pieces from the period. Aside from the omnipresent harpsichord, the baroque period also contained several hangovers from the Renaissance period, including recorders, viols, lutes, flutes and a whole range of string instruments that gradually fell out of use.
Baroque pieces Religious music was a huge part of the Baroque period, but it took composers like Handel and Bach to make them into emotional, human experiences. There are so many landmark pieces in the Baroque repertoire that it's difficult to pick just one. But let's give the 19 pieces of Baroque adagios a go. (from internet)