1: During the Renaissance, music was the tool of humanistic struggles. Classical music did not have a direct social goal. It was mainly regarded as an object of art.
2: in renaissance the communication via music was direct. Due to it, vocal music was more popular than instrumental one. For the composers of the Classical period, lyrics in music were not important.
3:During the period of Renaissance, musicians preferred such instruments as recorder and lute. The classical composers were charmed by the piano.
And finally, the changes can be noticed in the music structure. In the period of Renaissance, music was regarded as a flow of a stream. Due to it, the polyphonic structure with a combination of different musical lines was popular. In the Classical period though, the composers did not want to simplify music.
I really hope this helps
