Rock-n-roll promoter Alan Freed holds a talent search to develop a new rock star, then must find the elusive, mystery contestant (Jimmy Clanton) who doesn't know he has won.
| Actor | Role |
|---|---|
 Alan FreedHimself | Himself |
 Jimmy ClantonJohnny Melody | Johnny Melody |
| SSandy StewartJulie Arnold | Julie Arnold |
 Chuck BerryHimself | Himself |
 Jackie WilsonHimself | Himself |
 Ritchie ValensHimself | Himself |
| JJo-Ann CampbellHerself | Herself |
| HHarvey FuquaHarvey Fugua | Harvey Fugua |
 Eddie CochranEddie Cochran | Eddie Cochran |
| JJimmy CavalloJimmy Cavallo | Jimmy Cavallo |
 Herb VigranBill Barnett | Bill Barnett |
 Frank WilcoxHarold Arnold | Harold Arnold |
 Barbara WoodellMrs. Arnold | Mrs. Arnold |
 Milton FromeMr. Martin | Mr. Martin |
 Joe CranstonBand Leader | Band Leader |
 Martha WentworthMrs. McGillicuddy | Mrs. McGillicuddy |
| IInga BolingAmy | Amy |
 Robert FoulkPoliceman | Policeman |
 Phil ArnoldCall Boy | Call Boy |
 William FawcettJanitor | Janitor |
 Dick ElliottMan in Phone Booth (uncredited) | Man in Phone Booth (uncredited) |
 Joe FlynnHead Usher (uncredited) | Head Usher (uncredited) |
 Judy NugentBlonde Fan (uncredited) | Blonde Fan (uncredited) |
| LLili RossonMalt Shop Girl (uncredited) | Malt Shop Girl (uncredited) |
 Adriano CelentanoAdriano Celentano (uncredited) | Adriano Celentano (uncredited) |