An album released nearly 50 years ago is now the No. 1 selling album of all time according to new certification from the Recording Industry Association of America (RIAA) which tracks U.S. sales and streaming equivalents.

The Eagles formed in 1971 and became one of the best-selling music artists of all time, winning six Grammy Awards. The Rock and Roll Hall of Fame group will soon wrap up a residency at the Las Vegas Sphere with the current lineup of Henley, Joe Walsh, Timothy B. Schmit, Vince Gill and Deacon Frey, the son of late co-founder Glenn Frey.

When you think about music, you think about how it connects people. How it speaks to different generations. But there’s something truly fascinating about those rare artists who didn’t just make great songs.

The best rock ballads of all time are also some of the best ballads period, from "Bridge Over Troubled Water" to "Dust in the Wind."