The award-winning actor premiered his first feature-directing effort at the Sundance Film Festival on Friday, where he received a standing ovation from the capacity crowd.
"One of the many gifts that have come to me from directing... is that I've fallen in love with this business all over again," the 63-year-old said before his film's world premiere.
"Rudderless," which Macy helped write, tells the story of a father who discovers and performs his son's original songs after the college student dies in a campus shooting. Billy Crudup, Anton Yelchin and Macy's wife, Felicity Huffman, star in the drama that screened as the festival's closing-night film.
Co-writers Casey Twenter and Jeff Robison, both new dads, said they "wanted to write a story that could be an example of unconditional parental love."
Macy said they didn't want to make a movie about gun control.
"I have the feeling that if I gave a handgun to every single person in this room, that the chances of something bad happening go up pretty exponentially," he said. "On the other hand, I love to shoot. I love to plink, and I have nothing against hunting. It's a complex problem."
He was so excited to unveil his film at Sundance that he took several photos of the audience from the theater stage before the screening began. He told the crowd to raise their hands and yell, then said, "You won't mind if that's what I say you did at the end of the film.
The film has not yet been picked up for distribution.
Both Crudup and Yelchin performed the outstanding original music featured in the film. Indie rocker Ben Kweller also has a small role, as does Macy.
He said making the film was the most intense and most invigorating work he's ever done.
"I really want to try this again," he said. "I love directing."
The Sundance Film Festival wraps on Sunday.
Follow AP Entertainment Writer Sandy Cohen at www.twitter.com/APSandy.