About four times a week, before heading to bed, George Gaffoglio retreats to the upstairs bedroom of his Irvine, Calif., home, where he settles on his couch, picks up his guitar and fires up his laptop.

LOS ANGELES — About four times a week, before heading to bed, George Gaffoglio retreats to the upstairs bedroom of his Irvine, Calif., home, where he settles on his couch, picks up his guitar and fires up his laptop.

For the next half-hour or so, the 54-year-old sets aside his daily worries and dives into a website called ArtistWorks, where he plays along with instructional videos by Martin Taylor, attempting to mimic a British jazz guitarist who has collaborated with George Harrison, Dionne Warwick and other musicians.

"It's my therapy," said Gaffoglio, chief executive of an aerospace prototype manufacturing firm and a longtime ArtistWorks subscriber.

Based in Napa, Calif., ArtistWorks has a dozen professional musicians on its faculty offering thousands of hours of video lessons, from basic techniques to master classes. Among the instructors are Billy Cobham, a drummer who recorded and toured with Miles Davis, and Tony Trischka, a banjo player who produced Steve Martin's Grammy-nominated album "Rare Bird Alert." Martin himself appears in several ArtistWorks videos.

Since launching the service in June 2009, ArtistWorks has amassed more than 32,000 videos in more than a dozen genres, from classical piano and bluegrass fiddle to traditional mandolin and turntable scratching. The privately held company does not disclose its revenue or number of subscribers but says they number in the tens of thousands. By aggressively adding new instructors, the online academy expects to triple its revenue this year from 2011.

Instructional videos are hardly new, having been around in the form of DVDs, CDs and VHS tapes for decades. But online classes hold the promise of enabling teachers and students to communicate — even when they're across the world from each other.

In an age when the traditional music business structure is crumbling, companies such as ArtistWorks are offering a new path for musicians to make money.

"This is part of the general trend of social media breaking down barriers between artists and fans," said David Pakman, a partner with New York venture firm Venrock. It's also part of a general wave of people with knowledge using the Internet to share their skills, Pakman said, citing as examples online learning start-ups including TurnHere for video production, oDesk for technical instruction and Behance for creative design. "These new marketplaces for knowledge workers are great uses of the networked economy."

For online music instruction, the options include TrueFire, JamPlay and WorkshopLive. But few offer or emphasize the ability to carry on a regular dialogue with instructors, said David Butler, the 57-year-old founder of ArtistWorks.

A programmer who helped build AOL's Internet platform from 1988 to 1999, Butler picked up jazz guitar as an adult and was frustrated by his lack of progress with the slew of self-help videos and books he purchased.

He eventually found a teacher in 2006, jazz great Jimmy Bruno. But Bruno lived in Philadelphia, and Butler in Napa. Butler persuaded Bruno to do their lessons via online video conferencing.

"Those didn't work very well," Butler said. "You could see the person, but sometimes you couldn't hear them. Either that or the video and the audio wouldn't be in sync."

Butler spent the next two years building technology that would let Bruno convey his lessons online and interact with his students. Instead of dealing with the technical difficulties of live video, in which two people communicate in real time, Butler came up with video exchanges.

Using that system, students upload to the ArtistWorks website videos of themselves playing a song, then ask for feedback. Days later, they get a video response from their teachers. This ability to get personal feedback from his teacher has kept Gaffoglio paying his $30-a-month fee.

"When I got my first response video from Martin (Taylor) about 10 days later, I was really surprised by how personal it was," Gaffoglio said. "I felt like I had a connection to him."

The two struck up a relationship via emails and video exchanges. And when Taylor gave a concert in Dana Point in September, Gaffoglio went to meet his instructor for the first time. They had lunch afterward and talked about the instrument they both owned, a rare $10,000 handmade Mike Vander acoustic guitar.

They also discovered they had something else in common. Taylor toured the world, giving concerts and master classes. Gaffoglio, as the head of a company with 300 employees and clients in Asia, Europe and South America, spent much of his time on the road and in different time zones. For him, being able to access the guitar videos on his iPad or laptop whenever he had 30 minutes to spare was key.

"This ability to time-shift interactions is really a spark of genius," said Mike McGuire, a media analyst with Gartner Inc. "As people get further into communication and information overload, the ability for us to pursue something we really love on our own schedules is increasingly important."

It's not just busy professionals who tune in to online music lessons. ArtistWorks attracts students from a broad demographic. Its bluegrass curriculum tends to appeal to older males, for example, while younger females are more likely to flock to its classical piano lessons.

Instructors say they appreciate the flexibility of being able to interact with students any time they want, as well as the regular income stream it provides. ArtistWorks faculty receive a portion of each student's $30-a-month subscription fee (the company would not disclose the split, saying its contracts are confidential). Teachers also jointly own the rights to the videos they produce. Some of the more popular teachers earn more than $100,000 a year, Butler said.

Trischka, who spends about 50 hours a month working on his bluegrass banjo lessons and interacting with students, would not say how much he makes from the service, but calls it "a steady income, definitely more than pocket change."

Being part of an online service solves another problem for Thomas Lang, a drummer who has played with such artists as Tina Turner, Robbie Williams and Mick Jones of The Clash. Like many accomplished musicians with a following, Lang had published several instructional books and DVDs on drumming. But he made very little money on those projects, partly because bootlegged copies ended up on file sharing sites and sidewalk vendors.

"That just eats massively into your income," Lang said. "With ArtistWorks, the video is streamed, so it's much harder to steal."

Unlike income from books or DVDs, which peak in the weeks after they are released then tail off dramatically, the money instructors get from ArtistWorks rises over time as enrollment grows. In 2011, the company said its number of subscribers jumped 85 percent.

Still, the market for music instruction is relatively small, said Russ Crupnick, a music analyst with the NPD Group Inc.

"There is a small but loyal cadre of fans and aficionados who work hard to be immersed in the artist experience," Crupnick said. "It is a niche though, probably less than 10 percent of fans. But today every penny counts — a lot."