Who are the biggest artists of every decade? I am curious (from 50s-2020s)

I am curious to know, female and male artists, groups, anything. I know in the 2000s Britney was popular so would she be considered one of the biggest artists in the 2000s along with others? I am curious of after 2000s too and way before 2000s as well. What would you consider the biggest artists of these decades like from the 1950s-2020s?