Toussaint Francois Battiste plays the title character in the world premiere of "Milo Imagines the World" at the Children's Theatre Company. (Kaitlin Randolph)

If the world is a canvas, as Henry David Thoreau wrote, then we are brushes painting our legacies onto it.

But if you’re a child in a place where plain adults create the rules, how do you assert some power?

Seven-year-old Milo shows that with creativity, children can shape their own stories. The title character of “Milo Imagines the World” is full of theatrical invention and can-do spirit in this new musical that’s up in an entertaining premiere at the Children’s Theatre Company.

Crafted in a range of styles by the musical theater team of composer Christian Magby and lyricist Christian Albright, and with a book by playwright Terry Guest, “Milo” is well-scored, briskly conducted by Sanford Moore and beautifully acted by its six-member cast.

Chicago-based director Mikael Burke stages it with subtlety and care. And even though the world of the show is actually very serious, with Milo getting lost in the subway, for example, the action still comes off as cheery, bright and surprisingly moving.

Even better, Burke and his creative team, including scenic designer Sydney Lynne and choreographer Breon Arzell, bring the story to life in a way that suggests that with his reveries, Milo is an inspired force of nature.

An hourlong one-act, the musical was adapted from Matt de la Peña’s 2021 picture book, and the plot doesn’t sound like much. Milo (Toussaint Francois Battiste) is on a long train ride on a Sunday with his big sis, Adrienne (Antonisia Collins). The siblings have natural tension, with Adrienne, who often is tuned into her phone and blocks out the world with headphones, ignoring the brother she finds annoying.

To pass the time on the ride, Milo imagines the lives of fellow passengers, drawing pictures and constructing whole narratives around them.

Lynne’s set credibly replicates a New York subway car, with doors that open and close as passengers enter and exit at various stops. The scenography and sound design evoke the milieu, including the breakdancers that are a regular presence on trains in New York. One welcomed absence: the rats that teem in the underbelly of the Big Apple.

Where the siblings are headed in “Milo” is a Samuel Beckett-esque mystery that hangs over the story until the very end. Even for those who know the narrative, the destination is not telegraphed at all, a delayed gratification that heightens the emotional payoff. Burke also gets us to stay totally in the moment with these characters as they come to life from Milo’s sketchbook.

Battiste is winning as Milo. He finds the character’s resourcefulness and keeps his light shining in the face of a tuned-out sister and an indifferent world. And he is a nimble dancer. Collins plays a typical teen, and from her gestures to her intonations, she carries out the role with assurance and intimacy.

The “Milo” ensemble includes China Brickey, who also is both heartbreaking and heartwarming as Mom, and Janely Rodriguez, who plays breakdancer Melanie. Breakdancing is not Rodriguez’s strong suit but at least it helps to tell the story.

The ensemble includes John Jamison II, who plays a nose-blowing cowboy who has lost his pet bird. Jamison shows another dimension of his talent on the twangy country tune, “How I Lost My Pet Bird.”

Keegan Robinson rounds out the cast as nattily attired subway rider Kevin, who Milo imagines to be carefree royal. Robinson and Battiste have a fun duet on “This Boy’s a King.”

In the end, Milo convinces those around him to see the world as he imagines it in a production that’s really a fun ride. Now, gentle readers, all aboard.