A simple technical test on the iTunes store last week shot an iVideosongs' podcast of a guitar tutorial to the top 10 of most-subscribed podcasts on iTunes.

The velocity of iVideosongs' (DEMO 08) viral growth since its January launch even surprises the Atlanta start-up's soft-spoken CEO Tim Huffman, who was nominated for a Grammy 25 years ago for a Gospel song.

"It's been like riding a horse downhill in a good way - we're gaining speed," said Huffman. "We've had fantastic traffic on our site- doubling every month."

The traffic is in response to iVideosong's twist to online music lessons that differs from competitors, such as Workshop Live and the U.K.-based Now Play It, because of the granular and visual way iVideosongs produces lessons. Huffman declined to say how many of the site's monthly 100,000 unique visitors convert to music lesson buyers.

The iVideosong Web site is a library of multi-camera, high-definition videos of master musicians talking about and playing some of their favorite songs - breaking songs down by chords and fingering techniques for musicians to follow. iVideosongs has attracted more than 100 notable artists from rock, folk, and country music.There's drummer D.J. Fontana, playing a half dozen of the 500 songs he recorded with Elvis Presley, talking about how Sun Records achieved its unique sound and Graham Nash showing the fingering nuances of playing"Teach Your Children." The songs - played by song writers or other famous musicians - include titles from The Beatles, Rush, Eric Clapton, The Rolling Stones, Jackson Browne, Loggins & Messina, White Stripes, Jet, the GooGoo Dolls, Kim Richey, and many others.

While online competitors have lots of songs and other content, iVideosongs not only has free, basic tutorials but something new, "How to play a song completely and accurately from beginning to end," said Huffman, who got into instructional videos in 1997 with the popular Blues Guitar Explorer CD.

iVideosongs' viral marketing campaign expects to build this month with a featured channel on YouTube and in about a week a featured MySpace channel offering free tutorials while it reserves paid transactions for its own site. Later this year, iVideosongs plans on offering songs through five of the top online distributors, Huffman said.

With 54% of every U.S. household home to an active - albeit often beginning musician -and the "aspiring musician" marketplace hitting US$17.9 billion in 2007 (according to Music Trades December issue), there is a lot of potential for the online music businesses. Digital sales of music represented 10% of the total worldwide music market in 2007, up from 6% in 2006, reports In-Stat. By 2012, digital music sales will represent 40% of all music purchased worldwide.

While musicians are the target for most online music businesses, iVideosongs has been "pleasantly surprised" by the number of music fans who aren't players downloading songs to watch famous musicians point out fingering techniques, share stories, and perform.

Partnerships with musical instrument companies such as PRS Guitars,Taylor Guitars, D'Addario, and Roland and associations with "airguitar" games Guitar Hero and Rock Band are helping build awareness, Huffman said.

The company has had some sales in England, Canada, and Brazil,including enough traffic from Brazil to warrant beta-testing a Portuguese-language version. The company is also experimenting with a Mandarin version.

iVideosongs offers three kinds of music instruction content. Free tutorials designed to improve basic to advanced skills.Complete and accurate songs, instructed by professional music teachers for $4.99. Complete and accurate songs, taught by the artists who wrote, performed, and produced them for $9.99. iVideosongs splits revenues with artists.

iVideosongs, which spent three years negotiating clearances for the songs it offers as video lessons, uses a watermark on its videos to protect against piracy and has also retained Greenburg-Traurig, the largest law firm in the music industry.

Private investors 18 months ago financed iVideosongs with $3.3 million and last week the company began negotiating for series B private equity financing through Gilford Securities in New York, Huffman said.