Watching Hugh Grant and Drew Barrymore in “Music and Lyrics” is like listening to the London Symphony play “Twinkle, Twinkle, Little Star.”

The individual players sound great, but the overall piece is simplistic, predictable, trite.

Proudly having spent my teen years in the 1980s, I can appreciate writer/director Marc Lawrence’s creation of Alex Fletcher (Grant), the decidedly less popular half of a smash ’80s pop band. Think Andrew Ridgely of Wham! or Nick Rhodes of Duran Duran. (If you know who they are, I have a pair of vintage checkerboard Vans to sell you.)

Fully convinced that capitalizing on his past fame is his only career option, Alex gigs karaoke-style at class reunions and amusement parks while the lone copy of his solo CD gathers dust in the discount bin at his neighborhood record store. He even seriously considers going on “Battle of the ’80s Has-Beens,” where yesterday’s stars actually face each other in the boxing ring before the winner gets a chance to sing.

A fantastic comeback opportunity appears when the Britney-inspired Cora Corman (newcomer Haley Bennett), the world’s biggest pop megastar, asks Alex to write a song for her new album. If she likes it, they’ll perform it together at Madison Square Garden. The catch? She wants it in three days, and Alex is terrible with lyrics.

During a fiasco of a songwriting session with a lyricist set up by his agent (Brad Garrett, whose formidable talents are barely glimpsed), the flighty but opinionated Sophie (Drew Barrymore) breezes in to water Alex’s plants, and he catches her subconsciously muttering better rhymes.

So the romantic tension begins. Sophie’s roped into a marathon writing and recording session that climaxes with a breathless rush to a waiting Cora at her helipad. She likes it! Alex’s career is saved! What possible plot developments could take up the next 45 minutes of the movie?

Like coyly switching the piano melody to bass clef in “Girl from Ipanema,” Lawrence tries to make the story interesting by throwing in a subplot involving Sophie’s former writing professor who’s unflatteringly turned her life story into a best-selling novel. Alex’s flaws are right on display alongside his over-moussed and puffy-shirted band photos that populate his apartment; the professor’s character seems contrived to prove that Sophie is more than just an endearingly dotty muse.

The songwriting duo parts ways when Cora’s laughably exotic and sexual interpretation of their earnest and heartfelt love song “simultaneously destroys two musical cultures” and Alex, mindful of where his next meal comes from, is fine with it. Sophie takes a stand for integrity, which in the pop music business apparently means the unemployment line.

“Music and Lyrics” gets kudos for lightheartedly taking on the challenge of inventing an ’80s band, and for striving to keep Grant’s performances realistic. The actor had only taken one year of piano lessons in his youth (from Andrew Loyd Webber’s mother, no less), but worked with a music coach to learn to sing and play several instruments quite passably.

And on the second-banana sidelines, Garrett is joined by comic tour-de-force Kristen Johnson as Barrymore’s Alex-worshiping older sister.

Hugh Grant has been criticized for being a “one-note” actor. That note’s in fine tune here, and it blends well with Barrymore’s harmony. Even with the addition of Garrett’s and Johnson’s tones, though, “Music and Lyrics” is just a simple C major chord progression, not a symphony.