Virtuoso double-bassist François Rabbath tells of a moment with an airline agent on the way home from performing in Australia. Could he check his instrument? The agent phoned her manager and Rabbath overheard him say, “One bass is OK, but not two.”

Unfamiliarity is one problem plaguing the instrument Rabbath fell in love with 70 years ago. Others include ungainliness (some have called it a “pachyderm”), a fingerboard that stretches from here to eternity, the physical strength it takes to play, and the fact that few composers have written for it. (“We hate Bottesini,” says Sylvain Rabbath, François’ son and accompanist on piano, of the 19th-century exception to the general rule.)

Yet in Rabbath’s embrace, the double bass sings as it never has in its 500-year history. Entirely self-taught, without ever learning the “right” way to play, he set it free. His importance to the double bass has been compared to Paganini’s to the violin.

The Rabbaths, pére et fils, will give a concert Thursday at the History Theatre in St. Paul. If you go, notice the end pin on his instrument — the pointy thing it stands on. On most basses, the end pin is straight up and down. Rabbath’s slants backward.

“It changes the center of gravity of the bass,” explained esteemed jazz bassist Rufus Reid, who considers Rabbath one of his greatest teachers. “Your body is more relaxed, and pretty much in the same position whether you’re playing way up in the upper register or down low. The playground — the fingerboard — is much more accessible. François plays all over the bass effortlessly.”

Learning to ‘pull the string’

Born in Aleppo, Syria, in 1931, Rabbath moved to Beirut with his family when his father lost his job. He took up the bass at age 13 so he could join a band with his brothers that brought in money. His sole instruction: “Pull the string in time.”

He saw a bass method book in a shop window, stole it, and toiled his way through it. The book was written in French, which he didn’t yet speak. Nor could he yet read music.

At 24, Rabbath, by then a highly accomplished if wholly unorthodox artist of the double bass, went to France with plans to attend the Paris Conservatory. He got in, but he couldn’t afford the lessons (which he paid for in tobacco), and he found the professor’s fingerings old-fashioned. So he went to work for people like Charles Aznavour, Jacques Brel, Édith Piaf and Michel Legrand.

He wrote and performed music for movies and the theater and began giving solo recitals. He played with the Beatles, Simon and Garfunkel and the Moody Blues. “In the ’60s and ’70s in Europe, if you needed a double bassist for a session of pretty much any kind, you called François,” said Twin Cities bassist Doan Brian Roessler, another student of Rabbath’s.

At the urging of Quincy Jones, Rabbath booked a recording studio. His first album of many, 1963’s “Bass Ball” (now a cult favorite), caught the ear of jazz saxophonist Ornette Coleman and the two became friends, performing together at Rabbath’s 1975 U.S. debut at Carnegie Hall.

The school of Rabbath

At 50, wanting more job security for himself and his family, Rabbath took a position with the Paris Opera, where he remained for 15 years.

He also started teaching. “I didn’t want to die alone,” he said. He wanted to share everything he had learned and discovered on his own, saving others the suffering of so much work. Rabbath’s students have included principal bass players in many of the world’s orchestras, for whom a diploma from L’Institut International Rabbath is a prized possession.

Roessler heard his first Rabbath recording in 2002. In 2007, he and his wife sold their house and moved to Paris for a year, taking their 2-year-old son and their dogs, so Roessler could study with Rabbath. On Roessler’s first day there, the phone rang. “Hey, Rabbath, it’s Ornette,” said the voice on the speaker.

Rabbath may be the best living example of a musician utterly indifferent to categories or labels. He just plays music: classical, jazz, folk, pop, world music, standards, originals, improvisations. He can make his instrument sound like a violin, a cello, a sitar, an orchestra, and a cry from the heart. He plays all of the Bach cello suites on the bass, in the original key, and some mean Paganini.

Composer and bassist Frank Proto has written five major works for him, including “Carmen Fantasy for Bass and Piano,” which we may hear at the History Theatre. Now 83, Rabbath “can’t play six hours a day anymore, but he’s playing better than ever,” said his son. “It’s crazy.”

“François is a true performer,” Reid said. “He lights up. He’s a leprechaun. He’s magical. He’s a pied piper. I don’t want to be super-syrupy about it, but he exudes this aura that makes you feel good.”