That uncomfortable echo between past and present hangs over Phamaly Theatre Company’s world premiere of “504: The Musical,” which opens Saturday, Aug. 8, at Denver’s Kilstrom Theatre. In April 1977, disabled activists occupied federal buildings across the country and announced that they would not leave until the regulations were signed. Goldberg and McDowell began writing “504: The Musical” in spring 2021 while attending NYU’s Graduate Musical Theatre Writing Program. advertisementActors Eli Schrouder, River Hetzel, Toby Yount, Maddie Stout and Jolee Harston rehearse a scene in “504: The Musical.” “504: The Musical” has a preview on Friday, Aug.7 and opens Saturday, Aug. 8.