Question: Off the Wall was a film that starred which actor known for roles in musical theatre?

Context paragraphs:
Love Birds (musical): Love Birds is an original musical with book, music and lyrics by Robert J. Sherman.  The musical officially premiered at the 2015 Edinburgh Fringe Festival at The Pleasance on August 7, 2015.  The production was directed and choreographed by Stewart Nicholls.  Prior to the Edinburgh run, there were two previews held in London at the Lost Theatre (in Stockwell) on July 28 and 29.  The Original Edinburgh Cast Recording was recorded on July 30 and mixed and mastered on July 31 and August 3 and was first released by SimG Records on August 12 at the Edinburgh Festival.  Two Edinburgh previews took place on August 5 and 6 with Press Night taking place on August 8.  The final festival performance took place on August 31.  The show starred Ruth Betteridge, Greg Castiglioni, John Guerrasio, George Knapper, Jonny Purchase, Joanna Sawyer, Anna Stolli, Rafe Watts and Ryan Willis.  In its end of the year round-up of regional British fringe musical theatre, "Musical Theatre Review" hailed "Love Birds": "a triumph of whimsy, a children’s story written with adult sensibilities and featuring a cracking score that celebrated the lost era of vaudeville.  Blessed with an equally strong design from Gabriella Slade and some marvellously sensitive performances, Love Birds was probably the most accomplished piece of musical theatre to arise from the many delights at this year’s festival."

Oh Sung-won: "Oh Sung-Won" (Hangul: 오성원 ; born October 22, 1972) is a South Korean musical theatre actor and crossover pop singer.  He has been active in musical theatre since 1999 such as "Elisabeth", "Rudolf", "Jekyll & Hyde", "The Last Empress", "42nd Street" etc.  He has taught at Hanlim Multi Art High School as the musical theatre department's chairman since 2011 and has also supported for Africa Dance/Theatre Academy as the representative of volunteer.

J. B. Adams: J.B. Adams (born September 29, 1954) is an American character stage and film actor, director, and singer.  He has credits in film, television and, most notably, musical theatre.  Originally from Oklahoma City, Oklahoma, he attended Oklahoma City University, where he studied voice, piano, opera, and musical theatre, after which he became a New York-based Broadway actor.  He is perhaps best known for his roles in the Broadway productions of "Beauty and the Beast" (as Maurice, the father), "Annie" (as Rooster/Drake/Bert Healy/FDR), "Parade" (as Luther Rosser), "Me And My Girl" (as Sir Jasper), and "Chitty Chitty Bang Bang" (as Grandpa Potts).  He played the role of Morris Farnsworth in the film "Far From Heaven", as well as originating the same role in the Off-Broadway musical adaptation (2013).  On TV and the web, he has played Santa for Verizon FiOS and has had guest starring roles on "" and "The Michael J. Fox Show".

Gerald Bordman: Gerald Martin Bordman (September 18, 1931 – May 9, 2011) was an American theatre historian, best known for authoring the reference volume "The American Musical Theatre", first published in 1978.  In reviewing an updated version of "American Musical Theatre" in 2011, "Playbill" wrote that the book had "altered the scope of American musical theatre history" and "remained the only book of its kind, and an invaluable one."

4th Wall Theatre, Inc.: 4th Wall Theatre, Inc. (aka 4th Wall Musical Theatre) is a non-equity theatre company in residence at the Westminster Arts Center on the campus of Bloomfield College, in Bloomfield, New Jersey, approximately 10 miles from Manhattan.  4th Wall is a qualified organization of the New Jersey Cultural Trust.  Gwen Ricks-Spencer currently serves as the Executive Director, while Kate Swan is the Artistic Director.  The group derived its name from the theatre term the fourth wall coined by Denis Diderot which describes it as “the imaginary wall at the front of the stage in a proscenium, through which the audience sees the action in the world of the play”.

David Ribi: David Ribi (born 1 August 1987) is an English actor known for his roles in West End Theatre and touring productions.  He trained in musical theatre at the London College of Music until 2006, and studied Drama and Theatre at Royal Holloway until 2009.

Patrick Cassidy (actor): Patrick Cassidy (born January 4, 1962 in Los Angeles, California) is an American actor best known for his roles in musical theatre and television.

Orville Harrold: Orville Harrold (17 November 1877 – 23 October 1933) was an American operatic tenor and musical theatre actor.  He began his career in 1906 as a performer in operettas in New York City, and was also seen during his early career in cabaret, musical theatre, and vaudeville performances.  With the aid of Oscar Hammerstein I, he branched out into opera in 1910 as a leading tenor with Hammerstein's opera houses in New York City and Philadelphia.  While his career from this point on primarily consisted of opera performances, he periodically returned to operetta and musical theatre throughout his career.  He notably created the role of Captain Dick Warrington in the world premiere of Victor Herbert's operetta "Naughty Marietta" in November 1910.

John Kenrick (theatre writer): John Kenrick (born October 3, 1959) is an American author, teacher and theatre and film historian.  Kenrick is an adjunct teacher of musical theatre history at New York University, Brind School – University of the Arts (Philadelphia) and The New School, and lectures frequently on the subject elsewhere.  His 2008 book "Musical Theatre: A History" is a comprehensive history of musical theatre from ancient times to the present.  Kenrick is the curator of the extensive musical theatre and film website "Musicals101.com: The Cyber Encyclopedia of Musical Theatre, TV and Film"

Off the Wall (1983 film): Off the Wall is a 1983 American comedy film directed by Rick Friedberg, written by Dick Chudnow, and starring Paul Sorvino, Patrick Cassidy, and Rosanna Arquette.

Supporting paragraphs: Off the Wall (1983 film) Patrick Cassidy (actor)
Answer: Patrick Cassidy