The document discusses how the band The Eagles started out as a backup band for singer Linda Ronstadt before becoming a successful band in their own right. It notes that the Eagles originated in Los Angeles in 1971 and consisted of Glenn Frey, Don Henley, Bernie Leadon, and Randy Meisner. The summary also highlights the Eagles' commercial and critical success as one of the most popular bands of the 1970s, achieving numerous number one albums and singles and winning several Grammys.