Patti LaBelle and Gladys Knight have earned their stripes as masters of soul music many times over. And on Sunday, they’ll prove it once more as participants in the next installment of the #Verzuz series.

LaBelle and Knight will meet at the Fillmore Philadelphia on Sunday at 8 p.m. to perform their hits (with no audience) in what many have called the series’ most anticipated battle yet. The show will be livestreamed on the Verzuz Instagram (@verzuztv) account and Apple Music.

“Gladys is my best friend, my sistergirl,” LaBelle said in an interview Friday. “We have to do this because we’re the original gangsters, we’re OGs.”

The #Verzuz series was created by Timbaland and Swizz Beatz earlier this year as a source of entertainment while many people were quarantined at home during COVID-19 red alerts. The popularity of the series has soared, with millions of viewers tuning in.

The Grammy-winning singers' battle follows other epic faceoffs: Brandy and Monica, Jill Scott and Erykah Badu, Babyface and Teddy Riley, Alicia Keys and John Legend.

“What we’re about to see are seasoned, beloved entertainers who extend beyond their genres," said veteran radio personality and celebrity strategist Dyana Williams. “They’re the original pop superstars.”

The Inquirer talked to LaBelle about the upcoming battle, her decades-old friendship with Knight, and why social media is going crazy about their reunion.

This interview has been edited and condensed.

How were you approached about the #Verzuz battle?

My son came to me and said, “Mom, would you like to do Verzuz?” I said, “Sure, with whom?” And he said, “Gladys.” Then I said, “We got to do this.”

And what a great person to do this with. We’re both Gemini, we’re both crazy, we both have kids, we both think sorta the same at certain times. I’ve been knowing her forever. I was with her when her son died, she was with me when my sisters passed. We’ve been together for so many years, so doing it with her is such a blessing.

People across generations are enormously excited about this. Have you seen any of the reactions on social media?

I’m a very old-fashioned girl. I have a flip phone, OK? As far as going on social media and stuff like that, I hear it from my son and different people, how everyone is excited about how awesome it’s going to be for [Gladys] and I to be together. I’ve been hearing so many wonderful things.

In this file photo, singers Patti LaBelle and Gladys Knight pose in the press room at the 2007 BET Awards held at the Shrine Auditorium on June 26, 2007 in Los Angeles, CA. Organizers of Verzuz said Tuesday the next installment of the viral Instagram Live series will pit Patti LaBelle against Gladys Knight. (Frederick M. Brown/Getty Images/TNS)
Frederick M. Brown / MCT
In this file photo, singers Patti LaBelle and Gladys Knight pose in the press room at the 2007 BET Awards held at the Shrine Auditorium on June 26, 2007 in Los Angeles, CA. Organizers of Verzuz said Tuesday the next installment of the viral Instagram Live series will pit Patti LaBelle against Gladys Knight. (Frederick M. Brown/Getty Images/TNS)
Why do you think this is touching so many people?

Well, I guess because of who we are. We’ve been in the business for about 60 years. Singing from the heart from the very beginning. Singing hard. Not compromising. I guess we’re like family, Gladys and I. Everybody can watch it together. The kids, grandma, grandpa, mom, and dad. People just want to hear great music. And with all the other Verzuz, you’re going to hear — and heard — great music.

I loved what I’ve seen from Verzuz, and to be in the category of all the duets that have done it, I feel great. Our music has stood the test of time. From the beginning until now, we’re both still relevant.

Will you be singing along with some of the songs?

Do I have a mouth? If God’s willing and the creek don’t rise, [I’m hoping to] have a voice on Sunday. I love singing live and I love singing to my music, I love singing a cappella. I just love to sing, so you can expect to hear anything from me.

We know that style and fashion is very important to you. Have you decided on a look for Sunday?

(Laughing) I decided about three weeks ago. I can’t share too much but it’s something that I think people will appreciate, I hope. I’m not going to go all out like I’m on stage, stage. But I’m just going to be Patti.

What are you looking forward to hearing from Gladys Knight?

“If I Were Your Woman." That’s my jam. And not only that, every song she sings I love. It’s like I’m a fan of Gladys Knight. It’s like singing with your idol.