This show: Walk Among the Boxes, actually consists of two interweaving story lines. The ‘Walk Among the Boxes’ storyline takes place in a modern setting. The second story line, entitled ‘Cat Hmpft’ takes place in the 1930s.
The soundtrack also consists of interweaving parts, moving back and forth between instrumental piano ‘Cat Hmpft’ music (set in the 1930s timeline), to guitar and vocal centric ‘Walk Among the Boxes’ pieces (set in the modern timeline.)
The ‘Cat Hmpft’ story line, perceived by the audience as a kind of flashback, takes place with action and music but no dialog. Ideally it would be staged as if it is akin to a black and white silent film. The main characters of the ‘Cat Hmpft’ story line are all jazz musicians and are seen frequently playing their instruments.