It’s a long weekend’s journey into night at Stick Fly, Lydia R. Diamond’s overstuffed play about an African-American family’s tumultuous reunion at their summer home on Martha’s Vineyard. Featuring an ungainly mixture of social, racial and economic commentary and soap opera-style histrionics about who slept with whom, this comedy/drama wears out its welcome long before the conclusion of its overly long running time. Featuring among its many producers the pop star Alicia Keys, who also contributed the original music, the play will face a steep uphill climb in the currently difficult Broadway environment for new pays sans marquee names in the cast.

Taking place in a lavishly appointed home that the Playbill pointedly informs us in not located in Oak Bluffs, the play introduces us to the LeVay men and the women in their lives. Patriarch Joe (Ruben Santiago-Hudson) is a neurosurgeon who--judging by the fact that he has shown up alone—might be experiencing some marital difficulties.

Eldest son Flip (Mekhi Phifer) is a well-heeled, cocky neurosurgeon who arrives with his new and very white girlfriend Kimber (Rosie Benton). His younger brother Spoon (Dule Hill), who has just finished writing his first novel, brings along his fiancé, Taylor (Tracie Thoms), a graduate student specializing in the study of insects (hence the title).

Also on hand is Cheryl (Condola Rashad), the young and pretty daughter of the housekeeper, who is temporarily filling in for her sick mother. Despite her modest upbringing, she’s been educated at one of Manhattan’s finest private schools.

Immediately, tensions start to flare among the group. The two brothers clearly have a sibling rivalry; Flip and Taylor were obviously once romantically involved in one way or another; and Taylor, harboring not-so-secret jealously, unleashes a racially and socially charged diatribe against Kimber.

But things go downhill even from there, with the revelation of a dark secret that turns all of the relationships upside down and threatens to drive everyone even further apart.

While the juicy melodramatic aspects of the play are entertaining enough, especially with the frequently nasty one-liners (most of them delivered by Phifer’s Flip) constantly being thrown about, the playwright gets in over her head when attempting to delve into deeper sociological issues. And the predictability of the plot twists proves wearisome, although clearly not to the many audience members who were gasping at the not exactly revelatory developments.

Director Kenny Leon is unable to bring any stylistic coherence to the evening, with the result that the proceedings seem to shift wildly between wacky farce and Eugene O’Neill-style drama. And although both Rashad, so powerful a couple of seasons back in Ruined, and Santiago-Hudson, who knows enough to underplay, both shine, the rest of the performers are undone by the broadness of the writing.

Cort Theatre, 138 W. 48th St. 212-239-6200. www.Telecharge.com.