Stefani, Spears among stars in Orlando tribute

Top names in music including Gwen Stefani, Britney Spears and Mary J. Blige came together Wednesday for a charity single to benefit victims of the Orlando gay club massacre.

Entitled "Hands," the song starts as a mournful piano ballad with vocals by Spears and Stefani before turning into an inspirational anthem.

"If a million hands can build a wall / A million hands can bring it down," goes a verse sung by rockers Imagine Dragons.

Other artists on the song include pop stars Meghan Trainor, Selena Gomez, Jennifer Lopez, Adam Lambert and Jason Derulo as well as country singer Kacey Musgraves.

Other performers include the Trans Chorus of Los Angeles and, in an appearance at the end of the song, the drag queen RuPaul.

The song went on sale on iTunes, with proceeds to go to three groups including the Equality Florida Pulse Victims Fund.

The song was co-written by Justin Tranter -- who has penned songs for Gomez and Stefani as well as Justin Bieber's hit "Sorry." Tranter has long been active on gay rights.

Forty-nine people were killed and another 53 injured on June 12 when gunman Omar Mateen attacked a gay nightclub in Orlando popular with Latinos.

The mass shooting was the deadliest in modern US history.

Lopez is involved in another tribute song to the victims, "Love Make the World Go Round," which is being recorded with Lin-Manuel Miranda, writer and star of the blockbuster musical "Hamilton."

Miranda and Lopez, who are both of Puerto Rican heritage, on Monday put out a video that showed them recording the song which has not yet been released.