“World’s Best,” from the director Roshan Sethi, is a vibrant kid’s musical set to a simple beat. The seventh grade calculus prodigy Prem Patel (Manny Magnus) longs to be as cool and confident as his dad, Suresh (Utkarsh Ambudkar), a rapper who died of cancer when the boy was five years old. Prem’s mother, Priya (Punam Patel), is proud to raise a mathlete — until Prem slips on his father’s gold chain necklace and dad magically appears to inspire him to bust a rhyme at the school talent show. “I’m like a memory remixed with a fantasy,” Suresh says with a grin. I’d go with hype man or hype ghost.

Suresh performed in the aughts, but wears ’90s Timberlands and worships the ’80s hitmaker Doug E. Fresh. Maybe the whiz kid can calculate the rate at which nostalgia flattens time? Yet, the script, by Ambudkar and Jamie King, is otherwise attuned to the emotional and comedic details, like when Priya seeks solace in a podcast on grief only to be interrupted by an ad for oat milk.

Still, we’re here for the music which builds from subtle, classroom-rattling percussion — imagine the sound of pencils clacking on retainers — to a Hype Williams homage filmed in a five-sided cube with a fisheye lens. The rapping is great but the lyrics are strained (“Think Pythagoras meets Dr. Seuss/Square my sides to find my hypotenuse”) and the music is tinny and canned. I think Sethi wants to emphasize that these ditties are fantasies, but the overall effect is too phony. What works is the high energy, kooky cast who fling themselves into the carefree choreography — especially Magnus, a mugging, contagious delight.

World’s Best
Rated PG. Running time: 1 hour 41 minutes. Watch on Disney+.