If the mean of a dataset is 25 and its standard deviation is 1.6, then. 1  68% of the values in the dataset will lie between MEAN-1SD (25-1.6=23.4) and MEAN+1SD (25+1.6=26.6) 2  99% of the values will lie between MEAN-3SD (25-4.8=20.2) and MEAN+3SD (25+4.8=29.8).
For the first time, during the Classical period most of the important stylistic advances that occurred can be observed most clearly in the instrumental forms: the symphony, concerto, sonata, and in instrumental chamber music (e.g., the Beethoven string quartets).
Role of Composers During the Classical Period. The Classical period is known as the age of enlightenment as the power shifted from the aristocracy and church to the middle class. During this period, the appreciation of music was no longer limited to the rich and powerful. Those belonging to the middle class became patrons of music as well.