Rob Cavallo is a record producer and A&R, most famous for signing and producing Green Day. He is currently Chairman of Warner Bros. Records.

Cavallo, born in Washington, D.C., moved to Los Angeles, California when he was about ten years old. As a teenager, he played in local bands, and after graduating from high school he began working as a recording engineer. Cavallo eventually graduated from the University of Southern California where he received a Bachelor of Arts degree in English Composition, Communications and Sociology in 1985. In the mid– to late 1980s, Cavallo worked with the so–called "hair metal" bands around Hollywood as a record producer. This continued into the 1990s, but when the "hair metal" scene died out, he began seeking out alternative rock bands to work with.

Cavallo currently lives in Hidden Hills, California with his wife Kim and children.

Cavallo was an in–house producer with the band Green Day. He has co–produced every album from their multi–platinum success Dookie to American Idiot. Cavallo has also produced four studio albums for the Goo Goo Dolls, 1998's Dizzy Up the Girl, 2002's Gutterflower, 2006's Let Love In, and 2010's, Something for the Rest of Us.

Adam Mitchel Lambert (born January 29, 1982) is an American singer-songwriter and stage actor. Born in Indianapolis but raised in San Diego, Lambert had dreamed of becoming a performer after appearing in numerous amateur productions in his childhood and adolescence. His passion overtook him when deciding to drop out of college, pursue his career, and perform in various professional theatrical productions across the world.

Lambert came to prominence following his appearance on the eighth season of American Idol. Although he was runner-up, Lambert launched a music career with the release of his debut studio album For Your Entertainment (2009) after signing with 19 in a joint venture with RCA. Debuting at number three on the Billboard 200, selling 198,000 copies in the U.S. in its first week, and reaching the top 10 in several countries worldwide, the album subsequently achieved international success with its singles "For Your Entertainment", "Whataya Want from Me" and "If I Had You". Soon after, he embarked on his first headlining worldwide concert tour, Glam Nation, making him the only American Idol contestant to do so in the year following his Idol season. The tour was followed by two live releases: an extended play entitled Acoustic Live! (2010), and a live CD/DVD Glam Nation Live (2011), which debuted at number one on the SoundScan Music Video chart. Lambert took executive producer credit and was a principal writer on his second studio album, Trespassing, which was released to critical acclaim on May 15, 2012.Trespassing made its debut in the number one spot on the Billboard 200 album chart, also topping the Billboard Digital Albums Chart and Canada's Digital Albums Chart.With this accomplishment, Lambert makes music history as the first openly gay artist to achieve the top charting position.

Joshua Winslow "Josh" Groban (born February 27, 1981) is an American singer, songwriter, musician, actor, and record producer. His first four solo albums have been certified multi-platinum, and in 2007, he was charted as the number-one best selling artist in the United States with over 21 million records in that country. To date, he has sold over 24 million albums worldwide, and is the top selling classical artist of the 2000s in the US, according to Nielsen SoundScan.

Groban originally studied acting, but as his voice changed, it developed into a "significant instrument". Groban attended the Los Angeles High School for the Arts, a free public school where students received a conservatory-style education. His life changed when his vocal coach, Seth Riggs, submitted a tape of Josh singing "All I Ask of You", from The Phantom of the Opera, to Riggs' friend, producer, composer and arranger David Foster. Foster called him to stand in for an ailing Andrea Bocelli to rehearse a duet, "The Prayer," with Celine Dion at the rehearsal for the Grammy Awards in 1998.Rosie O'Donnell immediately invited him to appear on her talk show. Foster asked him to sing at the California Governor's Gray Davis' 1999 inauguration. He was cast on Ally McBeal by the show's creator, David E. Kelley, performing "You're Still You" for the 2001 season finale.