Patti LaBelle is approaching a big birthday. “Eighty good ones, right? Eighty!” she says incredulously. “And it’s still getting better.” How are you going to celebrate on Friday? “It’s a surprise. My son’s not telling me anything, but I have my beautiful gown and my beautiful jewels ready. And I have another hairstyle for my outfit. I’m prepared!”

I ask her if she is still performing. She looks at me, shocked. Is she performing? Is she ever not performing? “Last week I got back from Kentucky, Detroit, Saint Louis and Atlanta. I spend at least seven months of the year touring.”

In her most famous incarnation, as the leader of the trio Labelle (alongside Sarah Dash and the phenomenal Nona Hendryx) singing the soul-funk classic, 1974’s Lady Marmalade, she wore a silver space-suit and boots that would put Elton John to shame (he was her pianist before he was famous). Today, she’s equally stylish – black ski-slope hair, huge eyelashes, ferocious silver nails, white diamond hoop earrings and a ruby ring you could land a helicopter on. Her skin is fabulous. She looks a good 20 years younger.

LaBelle is at home in Philadelphia, where she grew up, when we speak on video call. Her house is part Charles Saatchi, part Liberace – abstract sculpture behind her, glitzy chandelier above, shih-tzu barking in the background. When Lady Marmalade was released 50 years ago, it was already her second coming. In the early 60s, Patti LaBelle and the Bluebelles had hits with songs such as I Sold My Heart to the Junkman and cover versions of You’ll Never Walk Alone and Over the Rainbow. They were a classic girl group of their time – dressed in identical gowns, tiaras and gloves.

Lady Marmalade was the start of her outrageous era. Even today, the song is raunchy, particularly the chorus: “Voulez-vous couchez avec moi, ce soir?” Is it true that she didn’t know what it meant when she sang it? “I had no clue,” she says. “None of us knew it was about a hooker.” What did she think when she found out? “I loved it – voulez-vouz couchez avec moi,” she starts to sing. Was it empowering for women? “Well, for women who lived that lifestyle, yeah. And for women who didn’t live that lifestyle? They loved the song too.”

There have been more rebirths since then. The solo star who had hits with the epic ballads Somebody Loves You Baby, Since I Don’t Have You and You Are My Friend; the 80s dance queen who charted with New Attitude and Stir It Up; duetting with Michael McDonald for the US No 1 hit On My Own in 1986; the leader of the reformed trio Labelle who, in 2008, released the album Back to Now produced by Lenny Kravitz, Wyclef Jean and the legendary Philly songwriters Gamble and Huff. And then there is LaBelle the actor who starred in A Soldier’s Story alongside Denzel Washington and the celebrity cook whose sweet potato pie was so popular in Walmart that it was reportedly being sold on eBay for around $50.

LaBelle, born Patricia Louise Holte, started out singing in her Baptist church choir as a little girl. It didn’t take long for her to be recognised as a special talent. “Miss Chapman was the leader of the choir, and she said I could sing so well and put me in front as a soloist. I realised after getting a great ovation and a hallelujah from the church crowd that my voice was pleasant to the ear.”

That is an understatement – the power of her voice is such that she sometimes has nose bleeds while singing.

Nicknamed the Godmother of Soul, she has been compared with Aretha Franklin, the Queen of Soul. It’s funny, she says, people often assumed they were enemies, but that couldn’t have been further from the truth. “People like to create ugly stories about girls against girls. But no, there was never anything like that. Aretha’s my hero, and we were going to do a duet before she died.” That would have been amazing, I say. “It would have been more than that,” she says.

Patti LaBelle and the Bluebelles had their first hit when she was 18. Where did the name LaBelle come from? “My first manager, Harold Robinson, said I think your name should be LaBelle for ‘the beautiful’. To me I wasn’t beautiful but he saw it in me.” Did she really think she wasn’t beautiful? “I knew I wasn’t. I was cute, but I wasn’t beautiful.”

Did she ever lose her heart to the junkman in real life? She laughs. “Never!” Is that drugs? “Never have I done drugs. I don’t smoke, nothing. I’ve never smoked a reefer in my life.” On stage, she is outrageous and unembarrassable. “If I get a run in my stocking I ask someone in the front row to come and cut it off or if my lashes are down on my cheek I’ll give them to one of the audience. I’m the original drag queen. And I have such a gay following, that’s a blessing.”

Is the private LaBelle different? “I love that question! I’m very shy and laid-back off stage. I don’t socialise very well. Offstage I’m boring. I’m very boring. I am.”

Brilliant, I say, that can be the headline. What’s boring about you? “I don’t drink.” She stops to correct herself. “No, I do drink wine. I don’t swim. I don’t drive a car. I don’t go dancing at the clubs. I stay in the kitchen and I cook.”

Twenty-odd years ago, LaBelle gave the public a guided tour around her home on film. She took us to her gorgeous swimming pool and told us that she was starting to learn to swim in a couple of weeks. Ah, she says. It never happened. “I put my feet in the water and get on one of those little floaters, but I can’t swim. I’m afraid I’ll drown. I walk my dog, but that’s the most exercise I get.”

Otis Redding tried to teach her to swim in the 1960s. “I thought I was going to drown Otis because I was pulling him down with me. I loved Otis Redding, and I still speak to his wife.” Redding, who died aged 26, seemed so much older than his years. “He had an old spirit, you’re right about that. Such a gentleman, such a nice man to all of us, to all of the ladies in the world.”

She can’t say the same about some of the other stars she’s worked with, however. In her memoir, she alleged that Jackie Wilson tried to rape her backstage in the early 60s. Her voice saved her. After being dragged into a room by him and an accomplice, which they locked, she screamed “every bit as loud as I can sing”. They backed off and she escaped. “It was a sore spot in my life,” she says. “That’s all I want to say. It was shocking. As bad as it was, I learned a lesson about people in this world, who you want to trust but you can’t.”

LaBelle doesn’t like to focus on the negatives. She’s got so many positives to tell me about from her life in music. Most involve food, jewellery and playing cards. Take Elton John. As plain old Reg Dwight, he was her pianist when she toured England in the late 60s. “Every night after the show we’d go to my flat, play cards and I’d win pounds. I’d always send him home with Tupperware, with something to eat for the night or next day.”

Fast forward to the early 00s and she joined Elton for a duet in Vegas. “At the end, he took off this huge diamond ring shaped like a cross. I said, ‘Elton, don’t forget your bling.’ He said, ‘It’s yours. I’m giving it to you for all your Tupperware.’” Does she wear it? “I can’t ’cos it’s too big!”

LaBelle bonded with pretty much everyone in the business. “In the 1960s we opened the show for the Rolling Stones in LA and we thought people would boo us off the stage, but they gave us a lot of love.” Another fast forward. The Stones are playing in Philadelphia, and she gets a call from the drummer, Charlie Watts. “He said Mick and the guys would like you to cook for them. I said OK, but make sure you share it with the opening act.”

What gives her more pleasure: cooking or music? “Music, of course. Cooking is my sidekick. I luuurve music.”

One of the most appealing things about LaBelle is how she handles things when they go wrong. The most notable occasion was when she performed This Christmas at the national tree lighting ceremony in Washington DC in front of President Clinton. The backing singers didn’t make it to the stage, the cue cards were wrong and everything was out of sync. She handled the situation magnificently in a handwaving improvisation that included the lyrics: “Where are the background singers? Wooo! Oh baby, baby! It’s the wrong words on the cue cards; I don’t know the song.”

You know why so many of us love it, I say, because it shows us that we can get through the most horrific situations with humour. “Oh God! When things go really bad I make a joke of it. It was a funny, messed-up day, but I got through it.”

LaBelle has dealt with far worse than technical glitches and a dodgy performance. All three of her sisters died of cancer in their 40s. “I lost part of my life. They were everything to me. I was just saying, ‘God, please keep me here for a while. I don’t want to leave now.’ So when I turned 50 I thought I’d hit the jackpot.”

Did she ever lose her Christian faith? “I would cry a lot on the stage when I sang certain songs, but I never lost my faith. Never.” Is there a particular song that she associates with the girls? “Yes, I sing Wind Beneath my Wings for my sister Jackie because I was her hero, and she was mine, but she never really knew it.”

After Jackie died, she and her then husband/manager Armstead Edwards (they legally separated in 2000 after 31 years of marriage, and divorced in 2003) adopted Jackie’s two children. They also adopted two children of a close friend who died young. “It was the natural thing for me to bring them into my home, and they’re great guys.” Meanwhile, her biological son, Zuri, now manages her.

After Zuri was born in 1973, LaBelle had postnatal depression. Her friend, the singer-songwriter Laura Nyro, came to her rescue. “I was going through crazy postpartum moments and Laura was his godmother.” Nyro, who died aged 49, is another person she lost far too early. “When Zuri was a baby she would come in her van to my home and I was inside the house and she was outside sitting under the tree with Zuri, singing to him.” What astonished her is that Nyro told her she wanted a life just like LaBelle’s – a loving husband, comfortable home and a baby. “I was like, look at this girl who’s written all these beautiful songs wanting a life like Patti LaBelle.”

Despite being a household name, LaBelle has not had many hits. She is, however, exceptionally wealthy – worth an estimated $60m. She still sells records and performs to sold-out audiences. And eventually she monetised the food that she had cooked for so long for pleasure. She published the first of a series of bestselling cookbooks in 1997, and in 2015 Patti’s sweet potato pie sold millions after a YouTube video of it went viral. Has she made more money from food or music now? “Well, now they’re neck and neck,” she says happily. “I’m blessed.”

Although she and her husband separated more than 20 years ago, they are still close friends. “The love is not lost. It’s just that we couldn’t live together any longer.” In her early 70s she dated the drummer Eric Seats, 30 years her junior. At the time, she said Zuri was not best pleased that her partner was younger than him. These days, she lives alone with her dog. Would she like another man in her life? “Well, Patti’s not dead! That’s all I can say. I’m a living, breathing woman.” But there’s nobody at the moment? “Not yet, no. But there will be.”

For now, though, she’s dedicating herself to a new album. “Sometimes I’m amazed at some of the notes I can still hit and above. And some nights I might be a little under. You know, I’m human. Every night is not going to be mindblowing or fabulous, it’s going to be Patti LaBelle whoever she is at that moment. But I have no complaints.”

If you can hit those notes at 80, I say, you’re a freak of nature. “I don’t have a clue. All I know is who you’re talking to is who I am.” It’s almost 40 years since Patti LaBelle last had a hit single. Does she think she has another big one in her? “I have about 55,000 big hits left in me!” she cackles happily. “And you’ll hear them soon.”

• A picture caption was amended on 28 May 2024. Patti LaBelle, Nona Hendryx and Sarah Dash formed Labelle, not the Bluebelles as an earlier caption said.