Sheryl Kaller, director, and Pamela Gray, playwright of “A Walk on the Moon,” a world premiere musical at A.C.T. Geary Theatre, June 9-July 1, 2018, in conversation with Richard Wolinsky. “A Walk in the Moon” is based on the 1999 film with a screenplay by Pamela Gray. Sheryl Kaller is a Tony-nominated director whose most recent Broadway play was “Mothers & Sons” by Terence McNally in 2014. And among Pamela Gray’s other screenplays are “Music of the Heart” and more recently, “Megan Leavey.”