it hasen't people just think it has
yes it has changed over many years
The term "pop" is short for popular music. As long as music has been around there has been popular music. The sound of popular music has changed over the years the same way that fashion has changed over the years.
Because people's interest has changed over the years.
Wave rock has changed over the years because it has changed colour
has hats changed over the years
the music player had become a revolutionary devise tht has changed the surface of mankind
it was the clash and then nofx came :/ but nofx are a really good band though (my 2nd favorite)
Because the music has improved.
Computers have changed in many ways over the years. Technology has advanced< and it has become more easy to do stuff!
Music is always going to be around. In 40 years it may have changed a lot, but it will always be.
it changed by... well it changed... It just changed!