Joe Bonamassa was only 12 when he opened 20 shows for B.B. King and jammed on stage with the blues giant in 1989. Since then, the two-time Grammy nominee has released 24 solo albums, been a member of the hard rocking band Black Country Communion and performed side by side with such six-string stars as Les Paul, Eric Clapton, Lee Ritenour and Leslie West, one of his key early mentors.

But this 39-year-old singer and guitar hero’s biggest accomplishment may be in the form of a public service that can seen, as well as heard, on TVs, iPads and smart phones across the nation.

That service, unplanned though it may have been, is to provide PBS pledge drive viewers with a welcome alternative to watching yet another in-concert show by such PBS favorites as Andre Rieu, Celtic Woman and Andrea Boccelli.

“Out of the five Joe Bonamasa specials we have aired since 2000, we have raised nearly $150,000 in (viewer) pledges to date. He ranks among our top five music programs,” said Nancy Worlie,the associate general manager for content and communication for San Diego’s KPBS.

“Joe comes to San Diego about once a year and we typically offer tickets or pre-show meet-and-greet packages, as we are doing for his Dec. 14 show at the Balboa Theater, where our members get to go backstage and meet him. He’s fantastic and is always willing to work with us on that. Because of the consistency of his programs and the consistency of his success, we will continue to air them.”

Bonamassa’s success is mirrored at PBS stations across the nation.

Three of the New York guitar-slinger’s six PBS specials — this year’s “Live at the Greek Theatre,” 2015’s “Joe Bonamassa: Muddy Wolf at Red Rocks” and 2013’s “Joe Bonamassa: Tour de Force, Live in London” — have thus far aired 3,884 times on PBS stations in 171 markets in 49 states. On Tuesday, the album version of “Live at the Greek” earned a Grammy nomination for Best Traditional Blues Album.

While Bonamassa draws a good number of the 50-and-older viewers who constitute the majority of PBS’s audience, he draws even more between the ages of 18-49.

That suggests there is a formidable number of viewers who enjoy blues-rock and searing guitar solos, as well as his tributes to such pioneering blues icons as Muddy Waters. Howlin’ Wolf and Albert King. “Yeah, I’m like the edgiest thing on PBS, which is saying a lot!” quipped Bonamassa, speaking by phone from a sold-out tour stop in Indiana.

“Honestly, I owe them a huge debt of gratitude for doing this, time and time again, tour after tour. You know, I’ve never bene on a national talk show. I’ve sat in with the David Letterman band, but they’ve never allowed my band to play on any of those late-night shows…

“We’re as far out as can be, as far as mainstream media is concerned. They don’t think their demographics want blues-rock, and I’m not sure I disagree with them. So the fact that PBS has been so supportive — I mean, they put us on air for an hour at a time — I’mthe one should buy them a plaque.”

But his gradual ascent to national PBS music favorite was an organic process, not the result of any carefully calculated plan.

That ascent began with the 2009 release of his first DVD, “Joe Bonamassa Live From The Royal Albert Hall.” Filmed at the historic London concert venue, it features guest performances by Eric Clapton and former Manfred Mann singer Paul Jones.

“We recorded the Royal Albert Hall concert in 2009 — we did it ourselves — using all the money we had in the world,” Bonamassa recalled. “My thinking was: ‘If my career ends tomorrow, and this is my only shot at the big time, at least we wanted a photographic and audio documentation to show my grandchildren that I was “somebody,” for a moment’.”

Then fate intervened.

About half a year after the DVD’s release, Bonamassa was contacted by WHMT, the PBS affiliate in Albany. It airs in Eastern New York, Western New Hampshire and parts of Massachusetts and Vermont.

WHMT asked Bonamassa if he’d let them edit his two-hour-plus Royal Albert Hall concert DVD down to 60 minutes and to air it. He readily agreed, although he didn’t think his music was an obvious match for PBS.

“They aired it once during a pledge drive and raised $25,000,” Bonamassa said. “Then they aired it again and raised another $25,000. That got the attention of Joe Campbell, who is PBS’s Vice President of Fundraising Programming. They did a national pledge-drive campaign with it, and it just exploded.

“I think it was the perfect storm — the kind of program they needed and their viewers wanted — but they didn’t know how. It was like this happy accident and it worked for them and it worked for us. Collectively, it made (PBS viewers in) this country remember my last name! I owe PBS a lot. I owe them everything. They’ve done a wonderful job for me and raised funds for a good cause. It’s a win-win.”

Bonamassa has no manager or booking agent. For the past 15 years, he has produced and recorded all of his albums and videos. Yet, while he has total artistic and commercial control of all his work, he was happy to let PBS edit all six of his concerts that he has released on DVD.

“They do their own edits and air what they want, and that’s totally fine,” said Bonamassa, who cites “Austin City Limits,” “Antiques Roadshow” and “Charlie Rose: The Week” among his favorite PBS shows.

“My feedback comes every night on tour, when I stand in the lobby or backstage and meet the 50 or so folks that PBS sold (meet-and-greet) packages to. The PBS rep in each city always comes and thanks me. I thank them right back. As long as it raises money for them, that’s the whole point. They’re a great public organization that relies on support from viewers.

“I like you to use their slogan!”