Gabriel, the new Ambassador of Conscience honoree, and U2's The Edge, a former recipient of the award, attended an event to kick off the organization's Small Places Tour Wednesday at the Hard Rock Cafe.
The event outlined a preliminary list of 545 Small Places concerts -- that could grow in excess of 1,000 events -- in 50 countries.
Amnesty International said the tour is unique in that artists worldwide can participate to raise funds and awareness by performing benefit concerts, offering premium-seating packages or auctioning off meet and greets and other unique fan experiences during their regularly scheduled touring cycle.
"It was through the tours for Amnesty International that I first met many people around the world engaged in human rights work. It was these people and their extraordinary stories of suffering and courage that I found impossible to walk away from, so the Ambassador of Conscience Award means a great deal to me," Gabriel said in a statement. "I hope that the Small Places Tour on the 60th anniversary of the (Universal Declaration of Human Rights) will really help to reinforce and underpin this extraordinary document that has been crucial to the lives of so many citizens of the world, and to be a similar source of inspiration to all those who take part."