♪ Oh Jonah ♪ ♪ Oh, oh Jonah ♪ - Until the 1940s, male quartets dominated gospel recordings.

But Apollo Records, a small, independent label in New York City, decided to take a chance on gospel's star soloist.

- Mahalia Jackson's a direct beneficiary of Apollo saying, we're now gonna record blues, and gospel and various other kinds of Black music.

♪ There is power ♪ ♪ Power ♪ ♪ Wonder-working power in the blood ♪ - While Mahalia Jackson was an accomplished singer, on the Chicago gospel scene, her first album flopped.

And it would take nearly a decade for her to cut another.

To make a living in between, literally, she had to sing for her supper.

- There's this kind of magical gap in her recording career.

She was really waiting around for the industry to catch up with her.

- In 1947, she recorded a song about the promise of salvation and the necessity of getting closer to God.

♪ Move on up a little higher, Lord ♪ - The title: "Move On Up A Little Higher."

♪ Move on up a little higher, Lord ♪ ♪ Meet with the Hebrew children ♪ - "Moving On Up" is special for a number of reasons.

For a long time, we thought it was just a straight, inspirational kind of song, but now we realize it had a coded message of empowerment.

♪ Move on up a little higher, Lord ♪ - It was an old-time spiritual that I revived with the bounce, and so I started to sing it the way I hear the people singing in the congregation, in the church, around the home.

And, of course, when they heard that type of singing, it was the type that they liked.

- Her sound is completely different.

There's shouts interspersed, there's growls in there.

There's a sense of freedom that she has with it.

♪ All of God's sons and daughters ♪ - The way that song builds, and the way she gives herself license to really, kind of, nearly shout towards the end, is a direct contrast from what many of those mainline Black churches wanted outta gospel music.

It don't take all that, but yet, Mahalia Jackson was giving all of that.

It's as if it is to say, this song is for me, if it's not for anybody else.

♪ 'Cause I'll be waiting ♪ ♪ Oh, at the beautiful golden gates ♪ - The Bible said to go in the highways and the hedges and compel men to come to God.

This record is really a testimony of mine.

When I sing, "Move Up A Little Higher," I was really down, and the Lord really lift me, and it is still my best song.

- What was special about her voice?

What gave it its power?

What made it unique?

- She believed and trusted in God, and was not ashamed, and would let you know that.

She believed every word she was singing, and she wanted you to believe it.

She was very spiritual.

Very.

- The success of "Move On Up A Little Higher" proved the gospel could be both spiritual and profitable.

- When Mahalia Jackson sold two million copies of "Move On Up A Little Higher," she wasn't just selling to Black people.

She introduces lots of audiences in the United States, and around the world, to Black gospel music, right?

And through her success, like, adds a popular legitimacy to Black gospel.

("Freedom Highway" by The Staple Singers plays) - As sales of gospel records soared, Mahalia and other musicians increasingly hit the road.

♪ March for freedom's highway ♪ - Record companies would send a cavalcade of gospel artists around the country and really built up this sort of incredible audience for gospel music.