Why stop at just ‘Ragtime’?

It’s double exposure for musical collaborators Lynn Ahrens and Stephen Flaherty. International City Theatre is launching its 20th anniversary season with “Once on This Island,” the pair’s Caribbean retelling of Hans Christian Andersen’s “The Little Mermaid” as a star-crossed love affair between a peasant girl and a rich family’s son. Musical Theatre West’s offering, with a cast of 50, is Ahrens and Flaherty’s epic “Ragtime,” based on novelist E.L. Doctorow’s roiling portrait of America in the early 1900s. David Jennings, as tragic pianist Coalhouse Walker Jr., and Victoria Strong, as the archetypal, WASP-ish mother-turned-feminist, reprise their roles from the national tour.

* “Once on This Island,” Long Beach Performing Arts Center, 300 E. Ocean Blvd., Long Beach. Opens 8 p.m. Friday. Runs 8 p.m. Thursday-Saturday, 2 p.m. Sunday. Ends March 13. $35-$60. (562) 436-4610. www.ictlongbeach.com.

* “Ragtime,” Carpenter Performing Arts Center, 6200 Atherton St., Long Beach. Opens 8 p.m. Saturday. Runs 8 p.m. Thursday-Saturday, 2 p.m. Saturday-Sunday, 2 and 7 p.m. Feb. 27. Ends March 6. $20-$47. (562) 856-1999, Ext. 4. www.musical.org