Question: What musical was based on the 2003 film directed by Jon Favreau?
Context: Couples Retreat is a 2009 American romantic comedy film directed by Peter Billingsley marking his directorial debut, and written by Jon Favreau, Vince Vaughn, Dana Fox, Curtis Hanson, and Greg Beeman.  Vaughn and Favreau star with Jason Bateman, Faizon Love, Kristin Davis, Malin Åkerman, Kristen Bell, and Jean Reno.  It was released on October 9, 2009, in the United States.  The film was shot mostly on the French Polynesian island of Bora Bora.  This film has been rated PG-13. The Wolf of Wall Street is a 2013 American biographical black comedy crime film directed by Martin Scorsese and written by Terence Winter, based on the memoir of the same name by Jordan Belfort.  It recounts Belfort's perspective on his career as a stockbroker in New York City and how his firm Stratton Oakmont engaged in rampant corruption and fraud on Wall Street that ultimately led to his downfall.  Leonardo DiCaprio (who was also a producer) stars as Belfort, with Jonah Hill as his business partner and friend Donnie Azoff, Margot Robbie as his wife Naomi Lapaglia and Kyle Chandler as Patrick Denham, the FBI agent who tries to bring him down.  Matthew McConaughey, Rob Reiner, Jon Favreau, Joanna Lumley and Jean Dujardin also star.  The film marks the director's fifth collaboration with DiCaprio, after "Gangs of New York" (2002), "The Aviator" (2004), "The Departed" (2006) and "Shutter Island" (2010), as well as his second collaboration with Winter after the television series "Boardwalk Empire" (2010–14). Swingers is a 1996 American comedy-drama film about the lives of single, unemployed actors living on the 'eastside' of Hollywood, California during the 1990s swing revival.  Written by Jon Favreau and directed by Doug Liman, the film starred Favreau and Vince Vaughn, and also featured performances by Ron Livingston and Heather Graham. The Big Empty is a 2003 drama film directed and written by Steve Anderson.  It stars Jon Favreau as a struggling actor with a bizarre request from his neighbor to deliver a suitcase that he cannot open.  While there, he meets an unusual cast of characters, and starts to think this delivery might be more than it seems. Elf is a 2003 American Christmas fantasy comedy film directed by Jon Favreau and written by David Berenbaum.  It stars Will Ferrell, James Caan, Zooey Deschanel, Mary Steenburgen, Daniel Tay, Edward Asner, and Bob Newhart.  It was released in the United States on November 7, 2003 by New Line Cinema.  The story is about one of Santa's elves (Ferrell) who learns of his true identity as a human and goes to New York City to meet his biological father (Caan), spreading Christmas cheer in a world of cynics as he goes. Spider-Man: Homecoming is a 2017 American superhero film based on the Marvel Comics character Spider-Man, co-produced by Columbia Pictures and Marvel Studios, and distributed by Sony Pictures Releasing.  It is the second Spider-Man film reboot and the sixteenth film of the Marvel Cinematic Universe (MCU).  The film is directed by Jon Watts, with a screenplay by the writing teams of Jonathan Goldstein and John Francis Daley, Watts and Christopher Ford, and Chris McKenna and Erik Sommers.  Tom Holland stars as Spider-Man, alongside Michael Keaton, Jon Favreau, Zendaya, Donald Glover, Tyne Daly, Marisa Tomei and Robert Downey Jr. In "Spider-Man: Homecoming", Peter Parker tries to balance high school life with being Spider-Man, while facing the Vulture. Made is a 2001 American crime comedy film written and directed by Jon Favreau.  It stars Favreau, Vince Vaughn, Peter Falk, and Sean Combs.  It was Favreau's directorial debut. Chef is a 2014 American comedy-drama film written, co-produced, and directed by Jon Favreau, and starring Favreau, Sofía Vergara, John Leguizamo, Scarlett Johansson, Oliver Platt, Bobby Cannavale, Dustin Hoffman, and Robert Downey Jr. Favreau plays a professional chef who, after a public altercation with a food critic, quits his job at a popular Los Angeles restaurant and returns to his hometown of Miami to fix up a food truck.  He reconnects with his ex-wife and invites their young son to join him in driving the truck back to LA while selling Cubanos in various cities along the way. Cowboys & Aliens is a 2011 American science fiction Western film directed by Jon Favreau and starring Daniel Craig, Harrison Ford, and Olivia Wilde.  The film is based on the 2006 graphic novel of the same name created by Scott Mitchell Rosenberg.  The plot revolves around an amnesiac outlaw (Craig), a wealthy cattleman (Ford), and a mysterious traveler (Wilde) who must ally to save a group of townspeople abducted by aliens.  The screenplay was written by Roberto Orci, Alex Kurtzman, Damon Lindelof, Mark Fergus and Hawk Ostby, based on a screen story by the latter two along with Steve Oedekerk.  The film was produced by Brian Grazer, Ron Howard, Kurtzman, Orci and Rosenberg, with Steven Spielberg and Favreau serving as executive producers. Elf is a musical based on the motion picture of the same name, with a score by Matthew Sklar and Chad Beguelin.  The book is adapted by Bob Martin and Thomas Meehan from the 2003 film.  The musical ran on Broadway in the Christmas seasons of 2010-11 and 2012–13, and also toured the U.S. in 2012.  A new tour launched in 2014.
Answer: Elf