Next to the word “blues” in the dictionary, there ought to be a picture of B.B. King.

His vocals are the voice of the blues, while his guitar Lucille is the instrument from which the melancholy music flows.

And after more than 50 years in the business, the 81-year-old legend is still going strong. He’ll play at 7:30 p.m. Saturday at the Bangor Auditorium.

The longtime diabetic is keeping up a schedule that would exhaust a much younger man. After playing in New England this week, he’s off to Brazil after Thanksgiving, then it’s back to the West Coast.

While other longtime acts are content to make nostalgia tours, recycling their hits over and over, King keeps producing. Earlier this year, he earned a 14th Grammy Award for his album “B.B. King & Friends: 80.” The release was a collection of duets with stars such as Elton John, Sheryl Crow, John Mayer and Eric Clapton.

“The thrill isn’t gone when you win an honor like this,” King said at the time. “Every time my peers recognize the work, it’s an honor, a reason to go on.”

When he could be enjoying a well-earned retirement someplace warm, what keeps Riley B. King going? Maybe it’s because he remembers how long the road has been to get to the top.

King was born amid the Delta blues, on a cotton plantation in the tiny town of Etta Bene, Miss., in 1925. He grew up playing for dimes on street corners, while working for a local farmer.

In 1947, he hitchhiked north to pursue his musical dream in another blues hotbed – Memphis, Tenn. He was fortunate enough to stay with and learn from his cousin, Bukka White, one of the most renowned bluesmen of that time.

He got his first big break in 1948, when he played on Sonny Boy Williamson’s radio show. This led to steady work in the local clubs and on radio. His stage name also got shortened from Beale Street Blues Boy King to Blues Boy King to finally B.B. King.

His treasured Lucille got her name in the mid-1950s. King was playing at a dance club in Twist, Ark. Two men started fighting, tipped over a kerosene lamp and set the club on fire. After he got outside, King remembered that he’d forgotten his acoustic guitar inside and ran back in to get it, barely escaping serious injury. After learning that the men were fighting over a woman named Lucille, he named his guitar after her, to remind himself never to do such a fool thing.

After his 1955 hit “Three O’Clock Blues,” King started touring nationally, and he has never looked back. He has gone on to create such hits as “The Thrill is Gone,” “You Don’t Know Me,” “Please Love Me,” “You Upset Me, Baby,” “Sweet Sixteen, Part I” and “Don’t Answer the Door, Part I.” Other concert favorites include “Payin’ the Cost to be the Boss,” “Caldonia,” “Everyday I Have the Blues” and “How Blue Can You Get?”

Rolling Stone rated King the greatest living guitarist, and listed him third all-time behind the late Jimi Hendrix and Duane Allman. His playing style of single-string runs punctuated by loud chords, subtle vibratos and “bent notes” has influenced two generations of rock musicians.

These later musicians returned the favor, with King playing or recording with such disparate acts as the Rolling Stones, U2, Clapton and Phish.

He’s become a cultural touchstone. The Beatles referenced him in their song “Dig It.” On “Sanford & Son,” the character Reiley, based on King, was Aunt Ester’s first love, who started his musical career after she dumped him. He’s been a TV fixture for decades, and his concerts have aired worldwide. He’s in both the blues and rock ‘n’ roll halls of fame.

But despite all the accolades, success comes down to being able to take the stage each night.

King summed up his performing style succinctly: “When I sing, I play in my mind; the minute I stop singing orally, I start to sing by playing Lucille.”

For tickets, contact the Bass Park box office at 990-4444 or Ticketmaster at 775-3331.