Jennifer Beals, 53, is an actress who has appeared in more than 50 films, including “Flashdance.” She stars in NBC’s new action series “Taken” and in the film “Before I Fall.” She spoke with Marc Myers.

The instrumental opener to “Get Down Tonight” by K.C. and the Sunshine Band has always had this magical effect on me. I first heard the song in 1975 on my clock-radio, when I was 12. I thought the intro’s high-pitched synthesizer notes sounded like sunshine and dolphins calling to each other.

Growing up in Chicago, I was pretty shy. At my school, most people had money, but my family didn’t. I also was biracial at a time when most people didn’t know what to make of it. So I was in my own world a lot. The only time I was fully myself was when I was dancing.

At 13, I heard “Get Down Tonight” coming through a set of large speakers. It was exhilarating. I was at a bar mitzvah and dancing with my friend David. There was a contest, and we won dancing to the song.

“Get Down Tonight” has always meant the expectation of something positive mixed with something more profound. After the dazzling intro, the song has an infectious, chunky beat and tightly arranged horns. Before disco became popular, little else sounded this energetic.

At that age, I had no idea the song’s lyric was code for sex. To me, “getting down” was only about dancing and letting go: “Baby face, I’ll meet you / Same place, same time / Where we can, oh, get together / And ease up our mind.”

Cut to 2005. I’m at a California hospital ready to give birth to my daughter. At one point, my contractions slowed, and I recalled having heard somewhere that dancing could help along the process.

So I connected my iPod to portable speakers, put on K.C. and danced with my husband to “Get Down Tonight” over and over. My daughter arrived an hour later.

This year my daughter will be 12—the same age I was when I first heard “Get Down Tonight.” She gets a kick out of the story every time I tell her, but when I played the song for her recently, she said it sounded like something they’d play at a sports arena. When I asked her why, she said, “To motivate the crowd.” Indeed.