Walter Parazaider, a founding member of the legendary rock band Chicago, has died at 81 after a heartbreaking battle with Alzheimer’s disease.

His wife, JacLynn Parazaider, confirmed the sad news to TMZ, revealing the beloved musician passed away just after 2 a.m. Wednesday while in hospice care.

Walter had been battling Alzheimer’s for six years.

“He had put up a good fight with Alzheimer’s and unfortunately it ended tonight,” JacLynn told the outlet.

“We are going to miss him for sure,” she added. “We were married for 59 years and we had 59 wonderful years.”

Parazaider helped launch Chicago in 1967, when the group was first known as The Big Thing. He formed the band with Lee Loughnane and James Pankow before the group went on to become one of the most famous and enduring acts in American music.

The original lineup included Parazaider on woodwinds, Loughnane on trumpet, Pankow on trombone, Robert Lamm on keyboards, Peter Cetera on bass, Danny Seraphine on drums, and Terry Kath on guitar.

Parazaider became known for his powerful work on saxophone, flute and clarinet. He also occasionally played guitar.

To millions of fans, he may be best remembered for his beautiful flute solo on the Chicago classic Colour My World. He also delivered memorable soprano saxophone work on the 1973 hit Just You ’n’ Me.

His musical fingerprints can also be heard on some of Chicago’s biggest songs, including 25 or 6 to 4, Saturday in the Park and If You Leave Me Now.

Parazaider revealed in 2021 that he had been diagnosed with Alzheimer’s disease.

“Needless to say, my wife, daughters and myself were shocked and devastated,” he wrote in a statement shared on the band’s website at the time.

“It has taken a while to process this news and the fact is, we still are,” he continued. “The good news is we have a wonderful medical facility here and I have a very good doctor. I am working hard and not going to give up.”

He added that with “new treatments and therapy” and the love of his family, he felt “very positive about the future.”

Parazaider had stepped away from touring years earlier. He retired in 2017 after developing a heart condition.

Looking back on the band’s rise, Parazaider once admitted that fame was never the original plan.

“I think for some guys in the group, it was harder to cope with the success than others,” he said more than a decade ago.

“I don’t think there were any of us that sat down around my kitchen table that day in February of ’67 and said, ‘Hey, our goal is to be famous.’”

But fame found them anyway.

Chicago became one of the most successful rock bands of its era, blending rock, jazz and horn-driven arrangements into a sound that helped define generations of American radio.

Parazaider is survived by his wife, JacLynn, and their daughters, Laura and Felicia.

His daughter Felicia shared an emotional tribute on Facebook after his death, writing that she did not make it back in time to say goodbye.

“My father, my hero, is gone. He went peacefully about 20 minutes ago,” she wrote.

“There’s no more pain. No more struggle,” she continued. “I psychically knew I wasn’t going to make it back in time. And I knew that it would be just my mom and him. It’s how it was in the beginning. Just the two of them. And so it should’ve been in the end.”

Felicia thanked fans for loving her father, even those who never met him personally.

“This was the worst six years. The hardest season of my life,” she wrote. “And I’m so grateful that my dad is not suffering anymore.”

She ended the tribute with a heartbreaking nod to one of Chicago’s most beloved songs.

“I love you poppy, my Pal. You coloured our world. God bless you, you dear soul. I love you beyond thoughts and words.”