"I've never spoken about this before, but my grandfather himself was a trailblazer. He was brave enough to come out in the 1960s, and I feel a lot of my spirit has come from him," Lovato said. "He passed away a few years later and I only wish he could have been able to see all the progress that has been made."
Logo TV's Trailblazers special comes on the one-year anniversary of the Supreme Court striking down the federal Defense of Marriage Act.
The "Heart Attack" singer was only one of many celebrities who attended the event to honor leaders in the LGBT community. Daniel Radcliffe, Adam Levine, Nate Ruess, Lance Bass, Joe Manganiello, the cast of Orange Is The New Black and Sia were also present at the gathering.
Logo TV's special will air Thursday at 9 p.m.
Notable deaths of 2014 [PHOTOS]