Jon and Al Kaplan

In 2002, Jon and Al composed, performed and produced a nine-song Silence of the Lambs musical, Silence! The Musical, which they put online so that they did not have to burn CD-Rs of it for their friends. Despite the fact that social networking sites like Facebook and Myspace had not yet taken hold, Silence! quickly became a viral sensation, appearing in magazines such as Entertainment Weekly and Maxim, and on radio shows like Opie & Anthony and Howard Stern's 100.

In 2005, the brothers composed several new songs and expanded Silence! into an actual musical. They wrote an Airplane!-styled screenplay, Silence! The Musical, that was adapted for the stage by Hunter Bell, and the show was mounted by director Christopher Gattelli at the 2005 NYC Fringe festival, where it won the "Overall Excellence Award" for Outstanding Musical. In 2010, Silence! re-opened in London at the Above The Stag Theatre to positive reviews. In June 2011, Silence! returned to New York, opening Off Broadway at Theatre 80, starring Brent Barrett as Dr. Hannibal Lecter and Jenn Harris as Clarice Starling. The NYC show moved to the Elektra Theatre at Times Square, closing in July 2013. In August 2012, Silence! opened at The Hayworth Theatre in Los Angeles and played 67 performances.

In 2008, Jon and Al composed their second full-length musical, 24: Season Two: The Musical. In 2014, the Kaplans finally began producing videos for the show and put them on YouTube.

In 2010, Jon and Al launched a series of one-off musicals on their YouTube channel 'Legolambs' that would feature entire movies distilled into single songs in a matter of three to four minutes. The most successful of the videos featured Al performing the singing voice of Arnold Schwarzenegger. Conan the Barbarian: The Musical,[1] Predator: The Musical,[2] Terminator 2: The Opera,[3] Commando: The Musical[4] and Total Recall: The Musical[5] are among the Kaplans' most widely seen works to date.

Jon and Al's musicals have also targeted Sylvester Stallone in Rambo: First Blood Part II and Peter Weller in RoboCop. Other YouTube musicals by the brothers include John Carpenter's The Thing, Super Mario Bros. The 8-Bit Opera, Schindler's List and Rocky IV.

In 2006, Jon and Al landed their first television scoring assignment as two of several dozen composers providing uncredited music for the NBC reality show Starting Over. (They were hired by another composer who was a fan of Silence! The Musical.) In 2007, they scored (for clarinet, violin and piano) the John Ford silent film entitled Just Pals, which was included in the "Ford at Fox" DVD box set. The Kaplans also wrote all of the Super NES-styled underscore for G4's cartoon series Code Monkeys, which ran for two seasons.

In 2010, Jon and Al scored The Hills Have Thighs, an erotic film that aired on HBO, Cinemax, Showtime and TMC, and also co-scored with Chuck Cirino the Syfy Channel original film Dinocroc Vs. Supergator, for which they delivered the spaghetti western theme that plays during the main title and several other times during the picture. In 2012, they scored Syfy's Piranhaconda.

In 2013 the Kaplans scored the horror feature Zombeavers, for which they also co-wrote the screenplay with Jordan Rubin.

In 2010, Jon and Al wrote, recorded and produced a short Lego video in which Darth Vader helps John Williams compose the Imperial march. On Aug. 30-31, 2013, John Williams introduced and showed the video at his annual Hollywood Bowl concerts with the L.A. Philharmonic. The short was again featured by Williams and David Newman during their 2019 Bowl concert.

After writing on several unsold pilots, Jon and Al were hired to write comedy for the 2009 MTV Movie Awards, where the final show featured their Best Song presenter patter for Leighton Meester and Lil Wayne.

While working as comedy writers on the 2009 MTV Movie Awards, Jon and Al arranged Andy Samberg's "Lonely Island Medley,"[6] which was performed by LeAnn Rimes, Chris Isaak and Forest Whitaker.