When the decade began, WHITNEY HOUSTON and AMY WINEHOUSE were still with us and BILLIE EILISH had just turned 8. SPOTIFY didn't exist in the US and people were buying MP3s. There were four major labels, down from five at the beginning of the previous decade and six just a few years before that. ADELE was an indie artist with some potential, TAYLOR SWIFT was a country star and DRAKE was a mixtape artist who had just signed his first record deal. Pop fans were obsessed with TIK TOK, which was a song by KESHA. People listened to albums. KANYE WEST wasn't getting along with the American president. Women had a hard time getting airplay on country radio and weren't treated as equals elsewhere and... oh wait, some things haven't changed. But so much has. The way music is distributed. The way it's marketed. The way it's heard. The way it's written and recorded. In the first decade of the 21st century, more than one visionary predicted music would soon flow as freely as water and electricity. These visionaries may or may not have understood that music would be cheaper, and way less lucrative, than those other seemingly free-flowing gifts. Or that its very accessibility would change almost every aspect of the music business, any maybe even music itself. In the second decade of the 21st century, music became water and drowned in its own undertow. And tried its best to learn to swim again. And in a decade where everything from $5 music-production apps to $50 professionally produced hip-hop beats to $500 wireless earbuds to $5,000 concert tickets to 50 million tracks of pop, hip-hop, country, metal, K-pop, reggaeton, techno and jazz was available at the click of a button to the world's 5 billion or so connected humans, the smart money, as always, was in touring. Or maybe the smart money was in digital distribution. Or artificial intelligence. The smartest money of all, though, from DRAKE to KAMASI WASHINGTON to the KNOWLES sisters to KACEY MUSGRAVES, was in making better music. Isn't it always? The stories below represent a slice of the 2010s as they happened in real time, along with newer essays trying to make sense of it all. You can find many more essays and lists in MusicSET: "Alright Alright Alright: The 2010s in Music." Happy new year and decade. MusicREDEF will be back in your inbox on Jan 6.