In a special tribute to acoustic music, Bob Dylan performed with the Avett Brothers and Mumford & Sons at the 2011 Grammy Awards.  Mumford & Sons opened the performance by playing "The Cave."  The Avett Brothers joined them on stage to perform "Head Full of Doubt, Road Full of Promise," which led into Dylan entering to perform.http://latimesblogs.latimes.com/music_blog/2011/02/bob-dylan-to-perform-at-the-grammy-ceremony-alongside-mumford-sons-and-the-avett-bros.html 

The 2011 Grammy Awards began at 8:00 p.m. EST on Sunday, February 13, 2011.  The ceremony took place at the Staples Center in Los Angeles, California, and aired live on CBS.  Other artists slated to perform at the event included Eminem, Dr. Dre, Mick Jagger and Lady Gaga.http://www.grammy.com/news/the-grammys-add-dre-and-dylan 

Mumford & Sons performed their single The Cave at the 2011 Grammy Awards.  The song opens with the lyrics, "It's empty in the valley of your heart, The sun, it rises slowly as you walk away from all the fears and all the faults you've left behind."  The performance was highlighted by the three-piece brass section and the cellist who accompanied the group.

The Cave appeared on the London folk group's debut album, Sigh No More.  The song also appeared in advertisements for Lastminute.com, in the World Cup of 2010, and in the Fox Network drama Lone Star.  It reached 99 on the U.S. Billboard Hot 100 charts in 2010.

Following the Mumford & Sons performance at the 2011 Grammy Award ceremony, a second curtain on the stage opened to reveal the Avett Brothers, set to perform on a stage designed to resemble an old-fashioned honkey tonk bar stage.  The group performed their single, Head Full of Doubt, Road Full of Promise from their album And Love And You.

Following the Avett Brothers performance on the 2011 Grammy Awards show, Bob Dylan appeared from behind a final rising curtain to perform Maggie's Farm.  The members of Mumford & Sons and Avett Brothers moved in to surround the singer, backing him up with all of the instruments their combined bands could provide, including banjo and accordion.  The singers from the combined bands provided back-up vocals for Dylan, who also performed on the harmonica.

Considered a pioneer of different schools of pop songwriting by MTV, Bob Dylan reached the height of his popularity in the 1960s as a vocalist.  His work has been covered by numerous performers throughout the years, perhaps most notably "Blowin' in the Wind" by Peter, Paul and Mary in 1963.http://www.mtv.com/music/artist/dylan_bob/artist.jhtml#biographyEnd 

Dylan won his first Grammy Award in 1972 when The Concert For Bangla Desh took home Album of the Year honors.  Over the next three decades he added nine additional Grammys to that first plus a Lifetime Achievement Grammy Award in 1991 for his career in the music world.http://www.grammy.com/nominees/search?artist=bob+dylan&title=&year=All&genre=All 

Consisting of brothers Acott and Seth Avett, the Avett Brothers got their start in Greenville, North Carolina, as members of the band Nemo.  They formed the Back Door Project with guitarist John Twomey, then changed their name to the Avett Brothers in 2000.  What followed was a self-titled album that year, and then a 2002 release of Country Was.  Several records later, the Avett Brothers caught the eye of Rick Rubin, who signed the group to his division of Sony BMG/Columbia.  In 2009, their release of I and Love and You reached number 16 on the charts, their highest placement at the time.http://www.mtv.com/music/artist/avett_brothers/artist.jhtml#biographyEnd 

Somewhat of a newcomer to the music industry, Mumford & Sons was formed in 2007 in London by friends Marcus Mumford, Country Winston, Ben Lovett and Ted Dwane.  After their debut album, the group played several concerts in Europe including the Glastonbury festival in 2008.  More recently, the band enlisted the help of producer Markus Dravs and worked with Glassnote Records to release c Sign No More.http://www.mtv.com/music/artist/mumford_and_sons/artist.jhtml#biographyEnd   The album that contains "Little Lion Man," which was nominated for the 2011 Grammy Award for Best Rock Song.  They also received a nomination for Best New Artist.http://www.grammy.com/nominees