Lovato, Jonas and Day paid homage to those who died in June 12 shooting, the largest in U.S. history. They included the late singer Christina Grimmie, who recently was shot and killed in the same city, in their tribute.
The singers also gifted Pulse employees with concert tickets and a private suite at the show, as well as a meet and greet opportunity, TMZ reports.
"Orlando you were incredible last night. Thank you @andradaymusic for helping DEMI and I are honor the victims of the terrible acts of violence recently," Jonas wrote on Instagram after the concert.
See how sports teams reacted to the Orlando shooting: