K-Pop classic or viral earworm? Either way, Gangnam Style was a 2010s music phenomenon. See what else defined the decade in the new CNN Original Series The 2010s, premiering Sunday at 9p ET/PT #2010sCNN | CNN Original Series

Can you remember your first tweet? See how social media changed America in the new CNN Original Series The 2010s, Sunday at 9 p.m. ET/PT #2010sCNN | CNN

How much do you remember about the pivotal social movements of the 2010s? Find out more in a new episode of the CNN Original Series #2010sCNN, Sunday at 9p ET/PT | CNN Original Series

CNN Headline News (partial), 10/26/1997