Earlier this month, Spears' collection of sexy, sparkling pop confections -- including the singles "Make Me" and "Slumber Party" -- topped iTunes' Pop Albums chart after the superstar's ever-loyal Britney Army launched the #JusticeForGlory campaign on social media.

Now, the Grammy winner has bestowed another gift upon fans: Friday's (May 29) surprise-drop of Glory's beloved bonus track "Mood Ring," previously only available in Japan. !

Less than a day after "Mood Ring" made its debut in all territories, Spears' legions of admirers -- through sales and streams -- helped it reach No.

'Mood Ring' is one of my favorite songs on Glory, it’s so vibey and sexy," Spears tells Billboard exclusively.

Arguably, no one is more in awe than songwriters Melanie Fontana and Jon Asher, who penned "Mood Ring" for Spears in 2015.

When I saw that she was putting out 'Mood Ring' for real -- like a repackaged single of sorts -- I just thought, 'Wow, you did it, kid.'".

Adds Asher, "In comparison to anything I've ever done, 'Mood Ring' feels like a destiny fulfillment.

that I would be working towards getting a Britney song.

1 song with Britney Spears.

The success of "Mood Ring" is truly a grassroots effort on behalf of the Britney Army and fans across the world.

RCA said that Britney's fans have been super active during quarantine and they wanted to basically reward them by releasing "Mood Ring." Still hard to believe it happened. .

I am well aware that when a song comes out as an international bonus track, 99 percent of the time, that is where the song is going to live forever.

I could see like Travis Scott sampling "Mood Ring." I would have expected that more than I expected this.

On streaming services, the song title is stylized as "Mood Ring (By Demand)." Obviously, its release is a direct response to years of begging from the Britney Army to make this song more accessible.

As songwriters, how does that love from the fans make you feel.

How would you describe the dialogue between you and the Britney Army over the last four years, regarding this song.

Asher: They have made us very aware over the years how much they love "Mood Ring." I care very deeply for the Britney Army.

Fontana: Every so often, I would go on Twitter and I would type in the words "mood ring." And I'd say about every third or fourth tweet would be about our song "Mood Ring," which was recorded five years ago at this point.

Fontana: "Mood Ring" was written by two lifelong Britney stans with only her in mind.

We had full-on Britney brain and really channeled her when we were writing the song -- lyrically, for sure, but also in the way we envisioned her performing it onstage or dancing to it in a music video?

But they asked, "Do you think it would be possible to write something for us like 'Mood Ring' that was a little more masculine?" And we said, "Sure." And so that's when Jon and I wrote "Setting Fires" for them.

And then "Waterbed" by The Chainsmokers used the original beat we wrote "Mood Ring" on.

It was June 2015 when I found out that Britney was cutting "Mood Ring" on her own.

But other than that, Mustard and Twice as Nice finessed it into something that was really true to Mustard's style at the time, and also really true to Britney?

Of all the tracks made for Glory, this one felt the most like classic Britney to me!

1 on iTunes' Pop Albums chart after fans launched the #JusticeForGlory campaign on social media, which also resulted in Britney issuing a new album cover.

Also, did you know there's a song that's on the Japanese edition that wasn't a global release?" It feels like the demand for both Glory and "Mood Ring" ping-ponged from person to person and it eventually made its way to Britney.

Britney Spears was definitely my "white whale," basically something I've been chasing for so long.

When I saw that she was putting out "Mood Ring" for real -- like a repackaged single of sorts -- I just thought, "Wow, you did it, kid." It's one of those moments where you have to zoom out on your career, and think, OK, that's definitely a big check mark on an amazing list of things that I've worked really, really hard to achieve.

Asher: I was introduced to Britney's music when I was 12, maybe even younger, and I would say my career spawned from my love for Britney Spears.

In comparison to anything I've ever done, "Mood Ring" feels like a destiny fulfillment?

that I would be working towards getting a Britney song.

The only tiny little twinge of sadness I felt was when I thought, like, dang, my mom or my friends in the States can't enjoy the song, unless they buy the CD from Japan.

Asher: Melanie and I were just ecstatic about even doing a song with Britney in the first place.

As a Britney fan growing up, that dream feels unreachable.

Asher: "My love is a mood ring, you change me." When we were writing that, I thought it was speaking to the fans.

Their love for Britney has changed her, they've helped her grow.  

Because you asked for it." Britney not only loves her fans, but, as she's proven throughout her career, she loves to cause a stir. 

I think a lot of Britney fans have felt unheard for a long time, so now to see their voices being heard is absolute magic

What are your expectations for listeners who are experiencing "Mood Ring" for the first time in 2020

Asher: Everybody in the world who is aware of pop culture knows who Britney Spears is

I hope that the people who are hearing it for the first time really give it a chance and allow Britney the room to breathe and grow as an artist. 

I would love to EP an album like that

When we get word from her team that it's time to start submitting, I'm gonna be first in line like, "Ding dong