Be careful what you say about the music when you come out of a movie theater, composer Brian Tyler may be listening.

Tyler has a ritual: The day one of his movies opens, he and the director theater hop, checking out how several audiences are reacting to the film and to the music. “I just pop my head in to see how the crowd is doing, kind of see how everyone is reacting,” Tyler says. “I really like to stand outside the theater and see if anyone is humming the music.”

Tyler is spending a lot of time at local cineplexes this month: two movies he scored opened last Friday,  Aug. 8: box office champ, “Teenage Mutant Ninja Turtles,” and “Into the Storm.” A third film, “The Expendables 3,” opens this Friday,  Aug. 15.

For “Teenage Mutant Ninja Turtles,” Tyler composed an old-school, often lush,  symphonic score. He and director Jonathan Liebesman both felt very strongly that “the turtles take care of the wackiness, we didn’t need to add to that.”  They also felt the tone should stay relatively light. “I didn’t want it to feel like a “Batman.” On the dark-to-fun-ometer, we wanted it to be a perfect ‘Raiders of the Lost Ark’,” he says. “There are some moments of ‘Raiders’ that are hardcore, but the overall feel is that it’s encased in an adventure film.”

“TMNT” won the box-office, despite receiving fairly negative reviews.“It’s not a movie made for critics,” he says. “It’s a movie made for people who want to completely let loose, so by design, the score that fits that the best is the kind of throwback adventure.”

So on the difficulty meter, I asked Tyler who is harder to write for: “TMNT’s” Michelangelo or “The Expendables’” Sylvester Stallone? Hands down, it’s the turtle. “I’ve known Sly for so long, I feel like I speak his language,” Tyler says. The fun in scoring his third “Expendables” film came in writing for the new characters, including Mel Gibson’s villain, “Stonebanks,” Just as Tyler played against the insanity of Teenage Mutant Ninja Turtles be keeping the score light, but not frivolous, he makes Stonebank’s theme a beautiful solo piano piece that plays in opposition to the character. “I thought more of an etude would work really great so it’s not just arch,” Tyler says. “It shows he has an interesting villainy; there are wheels turning in that brain.”

Tyler deployed a similar device with Loki’s theme in “Thor: The Dark World” by writing the piece on the harp. Tom Hiddleson, who plays Loki, loved the theme so much, he made a point of telling Tyler that he’d downloaded not just that selection, but the whole score.

In addition to “Thor,” Tyler has scored a number of Marvel movies, including “Iron Man 3” and is now working on Josh Whedon’s “Avengers: Age of Ultron.” He, of course, is sworn to secrecy about “Ultron," but says of the music, "It’s coming into shape. It’s going to be a great and long process.”

The key to scoring any Marvel film, “is that you want to completely buy the idea,” Tyler says. “Especially with the Avengers, you buy the idea that there’s a genius billionaire playboy and a big green monster. Josh directs it in a way that you have fun with it, but you completely buy it.”

Tyler is scoring —every pun intended— on the little screen as well.  He scores “Hawaii 5-0” and  received an Emmy nomination this year for his theme music for “Sleepy Hollow.”   Co-creator Alex Kurtzman and Tyler are friends and he approached Tyler about the supernatural thriller. “It was a blast,” Tyler says. “We wanted to make something that sounds quirky baroque, with violin, cello, a dulcimer and some percussion. It’s kind of a weird thing for a modern day TV show.”

Scoring a number of sequels allows him to sometimes get to know the actors, as he has Stone and Hiddleson. Through his work on the “Fast & Furious” franchise (he’s now scoring “Fast & Furious 7”), he became close to Paul Walker and the actor’s death still stings. In addition to the “Fast” series, Tyler also scored Walker’s 2008 film, “The Lazarus Project.” That was a labor of love for him,” Tyler says. “I wrote his theme for that and that’s what his family asked to have played as his memorial service. It’s called ‘Jaybird.’ He was really a great guy, just a sweet guy and outside the Hollywood system. He wasn’t interested in being a superstar, he’s rather be on a surfboard.”