| LLeon ThereminSelf – Inventor of the Theremin | Self – Inventor of the Theremin |
| CClara RockmoreSelf – Theremin Virtuoso | Self – Theremin Virtuoso |
| RRobert MoogSelf – Inventor of the Moog Synthesizer | Self – Inventor of the Moog Synthesizer |
| NNicolas SlonimskySelf – Composer and Historian | Self – Composer and Historian |
| PPaul ShureSelf – Musician | Self – Musician |
| HHenry SolomonoffSelf – Theremin Studio Member | Self – Theremin Studio Member |
| SSuki BaderSelf – Theremin Dancer | Self – Theremin Dancer |
| BBeryl CampbellSelf – Theremin Dancer | Self – Theremin Dancer |
| LLydia KavinaSelf – Theremin's Niece | Self – Theremin's Niece |
 Brian WilsonSelf – Founder of The Beach Boys | Self – Founder of The Beach Boys |
 Todd RundgrenSelf – Musician and Producer | Self – Musician and Producer |
 Vladimir LeninSelf (archive footage) | Self (archive footage) |
 Ingrid BergmanDr. Constance Petersen (archive footage) (uncredited) | Dr. Constance Petersen (archive footage) (uncredited) |
 Bobby BurgessActor in Mickey Mouse Show Clip (archive footage) (uncredited) | Actor in Mickey Mouse Show Clip (archive footage) (uncredited) |
| SSamuel HoffmanSelf – Mickey Mouse Show Clip (archive footage) (uncredited) | Self – Mickey Mouse Show Clip (archive footage) (uncredited) |
 Jerry LewisSidney L. Pythias (archive footage) (uncredited) | Sidney L. Pythias (archive footage) (uncredited) |
 Ray MillandDon Birnam (archive footage) (uncredited) | Don Birnam (archive footage) (uncredited) |
 Patricia NealHelen Benson (archive footage) (uncredited) | Helen Benson (archive footage) (uncredited) |
 Gregory PeckJohn Ballantyne (archive footage) (uncredited) | John Ballantyne (archive footage) (uncredited) |
 Michael RennieKlaatu (archive footage) (uncredited) | Klaatu (archive footage) (uncredited) |
 Barbara RushHelen Fields (archive footage) (uncredited) | Helen Fields (archive footage) (uncredited) |
 Joe SawyerFrank Daylon (archive footage) (uncredited) | Frank Daylon (archive footage) (uncredited) |
| JJefferson Dudley SearlesMr. Crow (archive footage) (uncredited) | Mr. Crow (archive footage) (uncredited) |
| AAlex TkaczevskiSelf – Translator (uncredited) | Self – Translator (uncredited) |
