Tom Ardolino is pictured on tour with NRBQ at Club Logo, Hamburg, Germany, in the late 1980s. (Photo by Jack Reich)

Tom Ardolino, whose ebullient drumming gave a rhythmic pulse to the nearly uncategorizable band NRBQ for nearly three decades, died Jan. 6 at a hospital in Springfield, Mass., of complications from diabetes. He was 56.

His death was confirmed by his brother Richard Ardolino.

NRBQ’s initials stood for New Rhythm and Blues Quartet, but the band could not be pigeonholed in any one style. Despite never having a top-40 hit, they maintained strong a following in live performances. Their fans included Elvis Costello, Paul McCartney and “The Simpsons” producer Mike Scully, who gave the group an animated cameo on the TV show. Bonnie Raitt once said Mr. Ardolino “deserves an entire wing in the Rock and Roll Hall of Fame” and compared him favorably to Rolling Stones drummer Charlie Watts.

“There’s Charlie Watts, and there’s Tom Ardolino,” Raitt told the Boston Globe. “That’s it.”

The band’s blend of influences — avant-garde jazz from leader and keyboardist Terry Adams, rockabilly and soul music from guitarist Al Anderson, and 1960s pop from bassist Joey Spampinato — could be catchy and jarring.

Bouncing up and down on his drum stool with a joyous, almost cherubic presence, Mr. Ardolino pulled the disparate strands together, often playing swing, polka, rock-and-roll and funk rhythms in the same night.

Writing in the New York Times, music critic Peter Watrous said Mr. Ardolino’s drum work “kept the backbeats secure, guaranteeing a dance impulse while regularly varying rhythms interacted with the soloists and never allowed the drums to fall into simple accompaniment.”

NRBQ toured relentlessly, sometimes up to 250 shows a year, and was known for its spontaneity. The group never worked from a set list and often performed impromptu, unrehearsed requests from an audience suggestion box. The results could be either brilliantly inspired or comically ragged.

Thomas Robert Ardolino was born Jan. 12, 1955, in Springfield. A self-taught drummer, he first heard NRBQ perform when he was 15, soon after the band was formed. He sent a fan letter to Adams and the two ardent record collectors were soon trading reel-to-reel tapes through the mail. When original drummer Tom Staley left in 1974, Adams gave Mr. Ardolino the job.

“I was ready,” Mr. Ardolino told the Baton Rouge Advocate. “My problem was I had to learn to play for like a whole set long, and [to play] harder, because I was used to playing with records, which was soft.”

His credits include the albums “All Hopped Up” (1977) and “NRBQ at Yankee Stadium” (1978), regarded by many as the band’s finest efforts. He also worked with Bob Dylan, Brian Wilson of the Beach Boys and John Sebastian of the Lovin’ Spoonful.

As a sidelight to his drumming, Mr. Ardolino compiled CD collections of song-poems, the vanity records on which nonprofessional lyricists pay allegedly professional musicians to set their words to music. However, he was frustrated when the bizarre records, which were never sold commercially, caught on with fans of outsider art.

“I knew when we started putting them out that it was going to be the end of finding them,” he told the New York Times.

NRBQ stopped touring when Adams became ill in 2004. Adams recently returned to touring under the NRBQ name with three new members.

Mr. Ardolino’s survivors include his wife, Keiko Ardolino of Springfield, from whom he was separated; two stepchildren, Emiko Ardolino and Liku Ardolino, both of Springfield; and a brother.

Reflecting on NRBQ’s lack of chart success, Mr. Ardolino was sanguine.

“One of our old record labels sent us a statement once claiming the total sales of one of our albums was three cassettes,” he told the Los Angeles Times in 1992. “But it ain’t gonna stop us.”

“Besides, I think we have a great life,” he added. “We get to play whatever we want, and we got to meet a lot of great people. I know all the good record stores in every town.”