John Duykers' first teaching position was as adjunct faculty at Mills College, where he taught private voice and conducted the madrigal singers (1971-73). From 1977-79, John was the Music Director of the Cazadero Summer Music Program (administered by the City of Berkeley, California). He evolved the offerings of this summer program to include world music, indigenous music traditions, baroque, jazz programs and family programs.
From 1979-81, he was the chairman of the Classical Music Program at Cornish Institute (now the Cornish College of the Arts) in Seattle, Washington. He helped develop a more diversified curriculum there, focusing on world music and composition.
From 1999-2004, Duykers was on the faculty of California Institute of the Arts where he developed the Opera Theater Performance Project with colleagues Lisa Sylvester and Melissa Weaver, creating 5 Pastiche Opera projects with the students and taught Performance Coaching.
In 2007-08, he was on the faculty of Frost School of Music at University of Miami, where he taught studio voice, German Diction, and created the Performance Articulation Laboratory for Singers (OperaPALS). He co-directed a pastiche opera (Cerberus Waits) and Dido and Aeneas with Melissa Weaver.
In the summer of 2008-09, he was on the faculty of Opera Works in Northridge where he taught acting for singers and co-directed the performance project.
He has given Master Classes across the country at UT Austin, USC, CSU Long Beach, the Metropolitan Opera San Diego Regional Committee, Sonoma State University, California Institute of the Arts, Cornish College of the Arts, and the Astoria Festival Young Artists Program.
He is currently voice faculty consultant and advisor for the Cornish Opera Theater at Cornish College of the Arts in Seattle.