KROQ's Almost Acoustic Christmas 2011: Florence + The Machine, The Black Keys, Mumford & Sons, And More (VIDEO, PHOTOS)

12/12/2011 03:53 pm ET | Updated Dec 12, 2011

For twenty-two years, KROQ's Almost Acoustic Christmas concert has provided a lineup of iconic rock groups at Universal's Gibson Amphitheater. Put on by LA's leading rock radio station, KROQ, the concert, which started as purely acoustic and now is mostly plugged in, sold out quickly this year, as it does year after year.

The first night lineup included classic rock groups Blink-182, Bush, Chevelle, Incubus, New Found Glory, Social Distortion, 311 and Young The Giant. The second night included both bands dating back to the early 1990s and bands that entered the scene within the past couple years: Jane's Addiction, The Black Keys, Florence + The Machine, Cage The Elephant, Death Cab For Cutie, Foster The People, Grouplove, Mumford & Sons, The Naked And Famous and Noel Gallagher's High Flying Birds.

According to MTV, the favorites of the newer bands were The Black Keys and Florence + The Machine. The Black Keys, which recently released its latest album "El Camino," won over the audience with a mix of old songs and new. And about Florence + The Machine, MTV wrote, "What a difference a year makes: Though Florence played last year's Acoustic Christmas and received a huge welcome from the audience, it was clear Sunday night that her fanbase has increased tenfold. Florence's presence has such a transformative effect on her fans--her movement during the songs, the shy smiles she sends out to the masses and that powerhouse voice all have the power to move people to tears."

As the Hollywood Reporter reports, the other crowd-pleaser of the weekend was a medley of beloved hits of the 90s. From Bush's Gavin Rossdale singing "Glycerine" to Sublime With Rome's "Smoke Two Joints" to Blink-182's "What's My Age Again", the audience sang along to every word and loved each second of it.

Check out some highlights below from KROQ's 2011 Almost Acoustic Christmas: