The musical wheels out well-trodden jokes about growing old while supplying all the usual greeting-card life lessons (live each moment as if it were your last!).

Monsters! A Midlife Musical Meltdown. Book by Gail Phaneuf. Music and Lyrics by Gail Phaneuf and Ernie Lijoi. Directed by Jerry Bisantz and Gail Phaneuf. Music Direction by John Kramer. At the Regent Theatre, Arlington, MA, through March 10.

By Alyssa Hall

Emily Browder Melville as Sam. Photo: Mak Kramer Photography

Monsters! A Midlife Musical Meltdown is more of a feel-good birthday celebration than a surprise party dead set on defying mortality. This original entertainment by New Englanders is refreshing because it features women in their 40s, a rarity for musicals, but otherwise the production at Arlington’s Regent Theatre sticks to the nice and predictable.

On Sam’s 40th birthday, as she considers quitting her Wall Street job to be an archaeologist in Peru, her inner demons (Apathy, Fear, and Body) appear to torment her in order to make her turn away from following her dreams. As this crisis unfolds, the show wheels out well-trodden jokes about growing old while supplying all the usual greeting-card life lessons (live each moment as if it were your last!).

Monsters! premiered in 2006 at the CentAstage in Boston and received two industry reads in New York in 2008. Though the show has been revised since those earlier presentations, the first act could still use more tinkering. The opening scenes, laden with exposition between Sam and her mother, drag and would have been more interesting if done via song, especially since the introduction of each of Sam’s monsters takes up almost the entire act. As a result, Sam, an indecisive character with a wet-blanket personality, spends most of the time reacting to everyone else’s criticisms instead of taking hold and driving the plot forward faster.

Luckily, the addition of each new cast member, the appearance of a mysterious, possibly bomb-containing gift, and the arrival of an unsolicited, singing birthday telegram girl ratchet up the energy, pushing Samantha into unhinged paranoia in the second act—inspiring amusingly zany antics, like Sam chasing Birthday Girl around the apartment with a bathrobe belt.

The characters are personifications of stereotypes (take, for example, Apathy as a frumpy, constantly eating 40-something and Body as a nitpicking, disapproving, male gay stylist), but the six-person cast—with agreeable voices and plenty of chutzpah—grabs on to those few traits and plays them up for pleasant laughs.

In the wrong hands, hesitant and increasingly paranoid Sam could be seen as scarily crazy or pathetically hopeless. Emily Browder Melville keeps her sympathetic rather than irritating by portraying her as sweet, silly, and confused. In some respects, the vagueness of Sam’s character makes it easier for us to see ourselves in her plight and commiserate, which, judging from the giggles and comments from the older people in the crowd, many enjoyed doing.

Birthday Girl diagnoses Sam’s phobias as the monsters protest. Photo: Mak Kramer Photography

Other cast members are equally successful at distracting us from the shallowness of their characters. Jennifer Fogarty, as Birthday Girl, mixes naïve, wide-eyed charm and earnestness with self-confident physicality to portray the “experienced psychology major” who comes to sing and stays to diagnose Sam’s phobias.

Lisa Beausoleil menaces melodramatically as the monster Fear, waving kitchen knives with glee and ominously predicting certain doom in “You Don’t Want to Know.” This campy approach fits with her creatively over-the-top, crazy bag-lady outfit: colorful, mismatched clothes, thick, badly applied makeup, poofed, frizzy hair, and shopping cart full of odd props like giant sunglasses and crystal balls. Her circus-act showmanship is captivating, and she stops just short of upstaging the rest of the cast.

As for the music, the cute keyboard riffs and lyrics quickly fade from memory after the show ends, but there are some nice harmonies. A few more songs such as semi-serious “Half of a Life,” when Sam evaluates her life decisions and goals, would be welcome. The creators favored more of the purely comic songs like “Dress Up” (Sam dresses in a mismatched outfit), which don’t particularly tell us anything new about the characters or advance the plot.

Monsters! invites you to a shindig best enjoyed by folks who like getting exactly what they expect for their birthdays. In this case, they get a present that wraps up nicely, even if it is a little rough in places: a lightweight, pleasant musical evening the offers those getting old some bubbly commiseration.