Jeff Cook, a co-founding member of the trendsetting Country Music Hall of Fame band Alabama, died Monday at age 73.

For a decade, Cook battled Parkinson’s disease, a progressive disorder of the nervous system that affects movement and causes tremors. He publicly disclosed his diagnosis in 2017.

A representative for the band confirmed his death Tuesday afternoon to the Tennessean. Cook died at his beachside home in Destin, Florida.

As a guitarist, fiddle player and vocalist in Alabama, Cook — alongside cousins Randy Owen and Teddy Gentry — helped sketch a blueprint for what a hitmaking band can achieve in country music. He and the band filled in that sketch with a slew of hits now considered by many to be essential country music listening: "Song of the South," "Mountain Music," "I'm In A Hurry," "Cheap Seats," and "My Home's In Alabama," among many others.

A native of small-town Fort Payne, Alabama, Cook began chasing his love of music on radio airwaves as a disc jockey in his hometown. In 1969, he co-founded the band Young Country alongside Owen and Gentry — planting the seeds for what later grew into Alabama. By the mid-1970s, the cousins performed as Wildcountry, cutting their teeth in nearby cities — like Myrtle Beach, South Carolina, where the band embraced a balance of country songwriting and Southern rock sensibilities on long nights inside local club the Bowery.

The band adopted a new name in 1977: Alabama. Two years later — after a run of modest radio success and adopting full-time drummer Mark Herndon — Cook, Owen and Gentry accepted an invitation to play the tastemaking "New Faces" showcase at the annual Country Radio Seminar in Nashville.

What came next? It might as well be country music history.

The band inked a deal later that year with RCA, beginning a remarkable run on the country radio charts. Alabama landed eight No. 1 songs on the country charts between spring 1980 and summer 1982, according to the Country Music Hall of Fame. That run included pop crossover hits "Love In The First Degree" and "Feels So Right," as well as "Tennessee River" and "Mountain Music" — staple Alabama songs that the group continued playing for decades to come.

And success didn't stall after this rocket-launched start in the early '80s. Between 1980 and 1993, at least one Alabama song topped the country charts every year. The band earned a slew of awards in that time, including a three-year run at CMA Entertainer of the Year from 1982-1984 and five ACM Award Entertainer of the Year trophies from '81-'85.

In a city dominated by solo artists and vocal groups, Alabama proved an instrument-playing band could forge a path to country success matched by few artists at the time.

“Country music was always about solo artists, and I think they capitalized on what the [o]utlaws had started, which was amassing a youth audience for the genre," country music historian Robert K. Oermann said in 2017. He added, "Jeff was the instrumental wizard who could do fiddle and guitar."

On stage, Cook held down fiddle, guitar playing and keyboards, adding layered backing vocals to the band's smooth, inviting melodies. His playing? It sent "people dancing all over the place," said Country Music Hall of Fame member Joe Galante, a former RCA executive who helped shepherd Alabama's career.

"... while he wasn’t front and center all the time, his contributions really made a difference when you listen for the hook," Galante told the Tennessean in 2017. "Those are hallmarks of records that will last well beyond our lifetimes."

For some, Cook's on-stage showmanship and behind-the-scenes friendship helped shape a class of entertainers to follow. Country hitmaker Kenny Chesney — who shared stages with Alabama early in his career — described Cook and the band as being "so generous with wisdom" during the singer's formative years.

Alabama showed a kid in a t-shirt that country music could be rock, could be real, could be someone who looked like me," Chesney said Tuesday. "Growing up in East Tennessee, that gave me the heart to chase this dream."

After an initial farewell tour that wrapped in 2004, Alabama reunited in 2011 for a charity concert benefitting tornado victims in the group's namesake state. In his time away from Alabama, Cook released a handful of solo projects. He toured with his Allstar Goodtime Band and released collaborations with Charlie Daniels and "Star Trek" star William Shatner.

Cook entered the Country Music Hall of Fame in 2005 as a member of Alabama — joining the most sought-after club in country music.

Alabama returned to touring in earnest with a 40th-anniversary celebration in 2013. Four years later, Cook scaled back performances with the band due to the ongoing impact of his Parkinson’s diagnosis.

He stopped touring with Alabama around 2018. As of 2019, his bandmates told the Tennessean they ensured his gear was set up before each show — just in case he wanted to step on stage. He co-wrote a song on a 2015 comeback album called "No Bad Days" that in time took a new meaning for the Hall of Fame musician.

“After I got the Parkinson’s diagnosis, people would quote the song to me and say, ‘No bad days,’ ” Cook told The Tennessean in 2019. “They write me letters, notes and emails and they sign ‘No Bad Days.’ I know the support is there. They join me. People I don’t know come up to me and say, ‘How ya feeling?’ You just got to live it every day and take it as it comes. Prayer does work. And I know there was a lot of praying going on.”

Cook is survived by Lisa Cook, his wife of 27 years. In lieu of flowers, his family asks for donations to the Jeff and Lisa Cook Foundation, a non-profit dedicated to raising awareness for Parkinson's disease.

A celebration of life plan to be announced at a later date.