As a piece of music, it's competent pop, competently performed and a bit outside my usual musical tastes; the (minimal) sets and costumes are properly evocative and hairstyles are spot-on. But the choreography, while incorporating modern elements that might have been too hot for the screen in their day, does a spectacularly good job of building from period-appropriate moves for each of seven different decades.
I stumbled over it channel-surfing.
It's worth watching. If you have to, play it with the sound off; but do play it. Dance is an element very rarely done right in "historical" film and this four-minute video manages to do it.
Quoth Wikipedia: "The music video for the song has received critical acclaim and praise for its homage to musical icons of the past such as Josephine Baker, Dorothy Dandridge,The Andrew Sisters, Diana Ross, Donna Summer, Janet Jackson and TLC. Hilson appears as each singer in a well-known scene from the era depicted."
2 weeks ago