How has music changed over the years?

There has been lots of change in the sounds. There have also been new singers with different voices bringing in different sounds. The instruments have changed as well example over 50 years back maybe acoustic were much more popular but its the electric guitar etc..... Music will continue changing with new instruments and new talent.

(I'm sorry if this isn't right I'm trying to do a term project on this question, if anybody has any links to a website with such information please type it in here. It would very nice of you.)