Michael was 12 when “I’ll Be There” ruled America for five weeks. Then a TV family came along.

In the fall of 1970, the most popular voice on American radio belonged to a boy who had just turned 12.

The Jackson 5 released “I’ll Be There” on August 28, 1970. The very next day, Michael Jackson celebrated his 12th birthday. By the middle of October, the song had climbed all the way to No. 1 on the Billboard Hot 100.

And it stayed there. For five straight weeks, nothing in America could knock it off the top.

It was the brothers’ fourth No. 1 in a row, and it was something new for them. Their earlier hits were fast and bouncy. This one was a slow, tender ballad, and Michael sang it with a feeling far beyond his years. Jermaine sang part of it too, trading lines with his little brother.

“I’ll Be There” became the biggest hit Motown had ever had in America up to that point. It even passed Marvin Gaye’s “I Heard It Through the Grapevine.” Tito Jackson has said the same thing himself: this was the record that replaced “Grapevine” as Motown’s biggest.

Here’s the song that made 12-year-old Michael No. 1.

The Jackson 5 sing “I’ll Be There”

Week after week, it held on. October 17. October 24. October 31. November 7. November 14.

Then came the chart for November 21, 1970. A new song jumped up from No. 4 to No. 1, and “I’ll Be There” slipped to No. 3.

It didn’t come from another Motown act. It didn’t come from a big rock band either. It came from a family band that most people had only met a few weeks earlier, on their TV screens.

Here’s the song that finally knocked Michael off the top.

The song that took over No. 1

That was “I Think I Love You” by The Partridge Family.

The Partridge Family was a sitcom that started on ABC on September 25, 1970. It told the story of a mom and her five kids who form a band and travel from show to show in a painted school bus. Just two months after the show began, its song was the biggest in the country.

But the band wasn’t really a band, and the family wasn’t really a family. Most of the music was played by top studio players. Only two people from the cast actually sang on the record.

One was Shirley Jones, who played the mom. The other was teen heartthrob David Cassidy, who played her oldest son and sang lead.

And here’s the twist. Off screen, they really were family. Shirley Jones was David Cassidy’s real-life stepmother.

“I Think I Love You” stayed at No. 1 for three weeks. But “I’ll Be There” is the song people still sing more than 50 years later, and the one that showed the world what 12-year-old Michael could really do.