There was a good reason Green Day had a "no cell phone" policy at their secret show at the Tiki Bar in Costa Mesa, California, on Thursday in support of the Cystic Fibrosis Foundation: They were debuting some new songs. In addition to giving some very lucky fans a peek at some fresh tracks they are working on for their next album, the trio also unwrapped "Amy," a brand-new tribute to late singer Amy Winehouse.

The touching, unplugged-style tune dedicated to the "Rehab" singer, who died at age 27 last month of as-yet-unexplained circumstances, alludes to Winehouse's troubled life and her signature fashions with evocative lyrics.

"Amy, is your heart singing out of tune/ Are your eyes just singing the blues/ Dirty records from another time/ Some blood stains on your shoes," go the opening lines, according to lyrics posted on the band's official website. A scratchy bootleg recording of the song features singer Billie Joe Armstrong crooning the 1950s-style doo-wop tune over a gently picked electric guitar.

"No one really knows about your soul/ And I barely even know your name/ Burning rhythms and posting lies/ For a bunch of fools drown in shame/ Amy don't you go/ I want you around/ Singin' whoa please don't go/ Do you wanna be a friend of mine?/ Did you tattoo a lucky charm/ To keep you out of harm's way?/ Warding off all evil signs/ But it never really kept you safe."

The final bit laments Winehouse's premature death and substance battles with the lines, "You're too young for the golden age/ 'Cause the record bin's been replaced/ 27 gone without a trace/ And you walked away from your drink."

The song ends with the emotional image, "May I have this last dance/ By chance if we should meet?/ Can you write me a lullaby?/ So we can sing you to sleep."

Green Day are the latest artists to pay tribute to Winehouse. The list includes U2, Coldplay and M.I.A.

In addition to "Amy," Green Day also previewed a number of other new songs during a full set of previously unheard tracks, including "Nuclear Family," "Carpe Diem" and "Sweet 16."

"Thanks everyone for coming out to the show Thursday night and supporting us and the Cystic Fibrosis Foundation," the band wrote on its site. "We have been in jamming and writing new songs for the last few months. It felt great to play these new Green Day songs live and share our 'work in progress.' Stay tuned for more!"