The world of physics is suddenly a very popular place to visit both on and off Broadway these days. On Broadway, the young hero of The Curious Incident of the Dog in the Night-Time has a penchant for it, and theoretical physics plays a major role in Constellations. Now it is at the forefront of a highly ambitious and complex new musical called The Artist and the Scientist, on view off Broadway at CAP21.

The CAP21 Theatre Company calls The Artist and the Scientist, with book and lyrics by Jenny Stafford and music by Brandon Anderson, a "concept musical." That's as good a description as any for a show that involves characters called Time (Dan Kohler), Space (EJ Zimmerman), Logic (Christina DeCicco), and Creativity (Curtis Wiley), all of whom circle around the titular Artist (Jamila Sabares-Klemm) and Scientist (James Penca) as they wrestle with their personal relationship.

Throughout the production, we are alternately invited to zoom in on the couple as they edge either towards marriage or a breakup, and then zoom out into the realm of their respective muses, Creativity and Logic, as they take sides. Creativity wants the pair to split so that the Artist can concentrate on her work. Logic believes that love will find a way and is dismayed when all of her calculations appear to have failed both her and the Scientist. To further complicate matters while Creativity and Logic debate their positions, we periodically zoom out yet more, to the vastness of the universe, where Time and Space—preparing to bring the planet Earth to its inevitable extinction—have taken an interest in the goings-on below.

So "concept musical" it is, with a truckload of concepts to juggle in two-and-a-half hours until finally Creativity and Logic are able to set aside their differences, and Time steps in to pull a trick involving "eternalism," which posits coexisting pasts, presents, and futures.

Musically, the show moves in an arc that is in sync with the book. The early numbers are mostly short tunes that are hard to characterize (introspective folk rock?), but as the show progresses, the songs become richer, more directly related to the storyline, and more lushly romantic, with multi-part harmonies that kick in as Logic, Creativity, Time, and Space come closer to accord.

One lovely example is a sweet number at the top Act II, called "See The World," which depicts the Artist and the Scientist as misfit children on the cusp of finding their muses. Also mitigating some of the show's serious scientific and philosophical tone is a very funny song called "Independent Foreign Film Art House," performed by the Artist and the Scientist as they voice their opinions about an abstract movie they are watching. All of the songs are accompanied most expertly by pianist and musical director Kristen Lee Rosenfeld and guitarist Craig Magnano.

The Artist and the Scientist could not be in better hands in terms of the acting. The cast is made up of seasoned professionals, and Ms. Sabares-Klemm and Mr. Penca (the perfect science dork) as the couple at the center repeatedly win our hearts, at least until we are asked to zoom out yet again. Director Jessi D. Hill manages to keep things in orbit, but, really, there are so many balls in the air, the presumably intended meshing of heart and intellect misses the mark; we simply zoom out way too far and way too often for everything to coalesce into a satisfying whole.

The Artist and the Scientist
Through February 28
Collaborative Arts Project 21 Theatre, 18 West 18th Street between 5th and 6th Avenues, 5th floor black box theatre
Tickets online and current Performance Schedule: fcny.org