O'Keefe and his wife Nell Benjamin collaborated on a short musical titled The Mice. The Mice was presented by Hal Prince as a part of the three-show evening 3hree at the Prince Music Theater in Philadelphia in 2000 and in Los Angeles in 2001. With Benjamin, O'Keefe has written two musicals for Theatreworks USA: Cam Jansen (2004) and Sarah, Plain and Tall (2002). In February 2004, O'Keefe guest-conducted the Harvard Pops Orchestra in an evening of his songs, and premiered his short opera The Magic Futon. A repeat performance with the Pops was presented in November 2008. O'Keefe worked with David Shiner on the music, lyrics, and book, for Drop Everything, a new clown show/musical, workshopped at ACT Theatre in Seattle. Excerpts were also produced at the Tollwood Arts Festival in Munich and the Lisbon Comedy Festival. O'Keefe and Benjamin wrote an operatic musical, first produced at New York's Fiorello H. LaGuardia High School of Music & Art and Performing Arts in 2012, titled Life of The Party. It was set in the Soviet Union in 1953 and based on true stories. It focused on the artists who labored under harrowing conditions to create Soviet movie musicals, trying to please both Stalin's regime and the public. The show later received a new workshop at New York University's Steinhardt School in March 2017. O'Keefe and Benjamin have written many songs and pieces for movies, television and concerts, including The Daily Show on Comedy Central, Johnny and the Sprites on The Disney Channel, Ant & Dec's Saturday Night Takeaway on UK's ITV, Defiance on SyFy, and Julie's Greenroom on Netflix. O'Keefe arranged and orchestrated the overture and other pieces of music for a Beatles tribute concert at the Hollywood Bowl, titled "Sgt. Pepper's At 40". O'Keefe and Benjamin contributed a new song, "This Is The Show", to the season finale of Best Time Ever With Neil Patrick Harris on NBC. They wrote narration and new comic verses for the New York Philharmonic's New Year's Eve 2015 gala, La Vie Parisienne. This was set to the music of Camille Saint-Saëns's Carnival Of The Animals, replacing the traditional introductory poems by Ogden Nash, and performed that night by Nathan Lane. Teaching and other work O'Keefe is active as a writer, teacher and advocate in the Broadway and New York theatre communities. He has served on the Nominating Committee of the Tony Awards. He is