EXCLUSIVE: David Foster Talks ‘American Idol’ & Living With Ex Yolanda Hadid's Lyme Disease: ‘We Did Our Best’

Alison Buck / WireImage.com

The 16-time GRAMMY winner was awarded for his contributions to the music industry at a glitzy gala at The Novo in Los Angeles on Tuesday.

Legendary musician David Foster is getting candid about his four divorces and opening up about his ex-wife, Yolanda Hadid’s, battle with Lyme disease.

“We just always did our best,” he said about living with Hadid’s illness, while talking to ET at the GRAMMY Museum’s third annual gala at The Novo in Los Angeles, California, on Tuesday. “We had some other issues as well, but everybody’s in a good place now. The main thing is that she’s healthy and in remission. She worked really hard at it and now she’s reaping the rewards of that.”

In her new book, Believe Me: My Battle With the Invisible Disability of Lyme Disease, the Real Housewives of Beverly Hills star claims the debilitating illness, which is spread by ticks, created cracks in her marriage, which ended in 2015.

“I haven’t read the book,” Foster, 67, said. “But she seems to be doing great. She’s healthy and living back east and happy and her kids are doing great, so it’s good.”

The couple’s divorce was finalized in May, marking the end of Foster’s fourth marriage -- something the Canadian GRAMMY winner joked about throughout the fundraising gala, where he received the Architects of Sound Award for his contribution to the music industry, and performed alongside celebrity guests.

As American Idol star Pia Toscano joined him on stage and remarked that married life with her husband of nine months, Jimmy R.O. Smith, was going well, Foster quipped, “Sorry,” before the pair performed hits by Celine Dion, whose career Foster helped launch.

Belting out Dion’s music alongside Foster was “an absolute dream come true” for Toscano, who is now a part of Jennifer Lopez’s All I Have residency at Planet Hollywood in Las Vegas. “When I was a little girl, I would listen to Celine and Whitney [Houston] songs and that’s what inspired me to sing and challenge myself as a vocalist, and David created all those masterpieces,” she told ET. “I would watch him on Oprah and think, ‘I hope one day I can work with him!’”

Foster’s good-humored marriage digs continued as singer/songwriter Sheléa joined him for a medley of hits that Foster worked on with another of his musical discoveries, the late Whitney Houston, for The Bodyguard.

“Sheléa always plays with Stevie Wonder and that’s how we met. Then we got married and then we got divorced,” joked the producer, who has received a whopping 45 GRAMMY nominations -- winning 16 -- for his work with icons including Houston, Dion, Michael Jackson, Michael Bublé and Barbra Streisand.

“Thinking about my divorces and the fact that all my ex-wives own half of everything…” he continued. “This first song [“I Have Nothing”] is actually owned by the plaintiff. Actually, all three songs are, but it certainly was a great time for me and Whitney!”

American Idol’s 2003 winner, Ruben Studdard, joined Foster to perform Earth Wind and Fire’s “After the Love Has Gone” (for which Foster won his first GRAMMY in 1980), before another Idol alum, Katharine McPhee, helped Foster debut a track from a Broadway musical he’s working on.

David Foster and Katharine McPhee perform at the GRAMMY Museum's 3rd annual fundraising gala in Los Angeles, California. - Alison Buck / WireImage.com

“He’s an incredible friend and I just pinch myself when I get to spend time with him on a personal level,” McPhee told ET before hitting the stage. “I love his outlook on life and how he treats people. He’s a really a special person in my life.”

“What I’ve learned from him is how lucky we are to do what we do,” the Scorpion star continued. “He’s always reminding me and it’s comforting to know that it’s possible to walk through this life he’s had -- working with incredible people, being friends with ex-presidents and world leaders -- and still have that perspective. He’s so well-connected, but still just a simple guy from Canada with his little Canadian accent!”

Music producer extraordinaire Quincy Jones presented Foster with his award, introducing him as “Canada’s most valuable export.” The honoree was accompanied by his daughters, Barely Famous stars Sara (and her tennis star husband, Tommy Haas) and Erin, who poked fun at her dad’s multiple marriages by sharing a video and pic of him with McPhee alongside captions including “Excited about my new step mom,” and “My parents.”

David Foster with 'American Idol' star Katharine McPhee. - Alison Buck / WireImage.com
David Foster with daughters, Sara and Erin. - Alison Buck / WireImage.com

The gala raised more than $1.2 million for the GRAMMY Museum’s newly expanded music education programs, largely thanks to an auction which saw one Foster fanatic from Austin, Texas, bidding $225,000 to have the musician perform at her home.

Foster’s longtime collaborator, Diane Warren, was also in attendance, describing him as brilliant and “the best musician I’ve ever met.” Video messages were played from others he has worked with, including Josh Groban and Seal, who joked, “Hi David, it’s your one black friend here.”

But it was the Idol stars who stole the show and Foster said he’s thrilled the series is returning on ABC next year. “I think the show coming back is fantastic,” he said. “I loved Idol the whole time it was on and I draw a lot of talent from that show. When I’m on the road, Pia, Katharine and Ruben have come with me and Clay Aiken comes sometimes. Jessica Sanchez and Jennifer Hudson have sung with me. It’s a great talent pool -- it’s like they’re doing half the work for me!”

See more on Foster in the video below.