In theater, Johnston has contributed to a number of productions over the years. Some of his important collaborators have included Hilary Bell, John Bell, Richard Foreman, Suzan-Lori Parks, Darren Gillshenan and Art Spiegelman.

He has done a number of score for the Bell Shakespeare, including Comedy of Errors (2002), The Wars of The Roses (2005), Measure For Measure (2005), The Merchant of Venice (2006) and Macbeth (2007). These were all directed by John Bell, with the exception of The Merchant of Venice, which was directed by Anna Volkska, for whom he also scored Twelfth Night at QUT.

He has also often collaborated with Australian playwright Hilary Bell (his wife since 1997) on songs and underscore for her plays The Falls (2000), The Anatomy Lesson of Doctor Ruysch (2002), and her adaptation of Molière ‘s The Hypochondriac (2018). This collaboration also extended to her libretto for his silent film score for F.W. Murnau’s Faust (1926/2002), her radio play Beautiful Hands (2010) and writing an additional song for her play Wolf Lullaby (1996)

Other  works have included songs for Venus by Suzan-Lori-Parks, directed by R. Foreman at the Public Theater (1996), Not Like Beckett (2007) by Michael Watts, for which he performed live on piano, ukulele, saxophone and percussion, Stepping Out With Mr. Markham (1997) by Jeanne Dorsey (Soho Rep), & Rain, Some Fish, No Elephants (1990) by Y York (New Theatre).


In modern dance, his most significant and long-running collaboration has been with choreographer Keely Garfield.  Their work together includes The Adventures of Slap & Tickle (1997, Lincoln Center), The Further Adventures of Slap and Tickle (1998, DTW), Minor Repairs Necessary (1999, DTW), Rub Me The Wrong Way (2000, 91st St Y), A Fishy Tale (2001, DTW/World Trade Center), & Good Girl Daddy (2002, Duke Theater on 42nd Street). Johnston was awarded the ‘Bessie’ (The New York Dance and Performance Awards) for best music for dance for his score for Minor Repairs Necessary in 1999.

Other significant collaborations include Karole Armitage’s The Predators’ Ball (which premiered at the 1996 Next Wave Festival at the Brooklyn Academy of Music) Emily Schottland’s Falling Girl (1985, DTW) and Persons With Slumber (1986, Merce Cunningham Studio) and Guta Hedwig’s Thirty (1998, Danspace)