 He also tried other innovative ensembles, including the quintet for violin, two violas, cello, and horn, K. 407, quartets for flute and strings, and various wind instrument combinations.He wrote six string quintets for two violins, two violas and cello, which explore the rich tenor tones of the violas, adding a new dimension to the string quartet conversation.Mozart's string quartets are considered the pinnacle of the classical art.