Rushing through the Capitol Hill light rail station one winter morning, I was stopped in my tracks by a man sitting cross-legged, dressed in all black, playing acoustic guitar. It's not every day I feel moved to give cash to a busker, but this guy was extraordinary, unleashing torrents of raga-folk bliss with an expert nonchalance that would have impressed Bert Jansch. I asked him his name and made a note to look him up online. That's how I discovered Patrick Neill Gundran, who regularly fills Sound Transit's acoustically splendid mezzanines with a rare sonic artistry that should make you yank out your earbuds and pay attention.

Gundran, who is nearing 50, has been busking since 2013—he started out playing in front of Virago Gallery (formerly Twilight)—but it wasn't until last summer that he took to it in earnest. Besides his acoustic-guitar workouts in public spaces, Gundran performs in more traditional venues in solo guise as Uneasy Chairs and in the groups the Colour Out of Space and devils/club. Gundran unleashes noisier splotches of grinding sound in these groups, which contain the yang to his busking persona's yin.

Gundran has no set schedule for busking. He may go three weeks without doing it and then set up shop for four days in a row. He prefers Capitol Hill's drafty station because of the great acoustics and the constant stream of pedestrians—things absent from the Beacon Hill flat where he lives. "I feel like I'm sitting next to a river with all the people flowing by," Gundran says during a break. Yet the mezzanine also gives him "a sense of seclusion."

Sound Transit currently allows busking at Capitol Hill and University of Washington Stations. It's "exploring options for expanding the program," says spokesperson Geoff Patrick, but no specific plans have been outlined yet.

Gundran certainly doesn't do this for the money—during the two hours I observed him, he earned about enough to buy a couple of drinks at nearby Nacho Borracho. However, one day a woman floated a $20 bill into his case after hearing the guitarist for a mere 20 seconds. "That's a dollar a second," he enthuses. "Impressive, right?"

What makes Gundran stand out from most buskers is his predilection for improvising rather than strumming familiar, catchy songs. Typically, he plays hard, forbidding blues licks that flow somewhere between John Lee Hooker and John Fahey, and he'll slip into a repetitive, trance-inducing progression in the vein of Peter Walker or Sandy Bull. Gundran's recurrent theme is music that meets where Delta blues shakes hands with raga-inflected folk.

It's strange to hear a street musician sound so fluent, so deep, so immune to the temptation to replicate beloved tunes. "I can never be a pro busker because I can't do covers well," Gundran admits. Instead, he taps into his vast reservoir of spontaneous creativity to loose eloquent, six-string streams of consciousness.

Sometimes Gundran plays a beat-up 1960s Silvertone guitar that he purchased for $100 in the 1990s because "it's great for slide." More often, though, he uses a "handmade no-name parlor that my best friend gave me last year. It's named 'Scarface' because of its cosmetic imperfections, which I keep adding to. It's basically a copy of a Martin 1-18, and it has an old bluesy Robert Johnson or early-Dylan vibe."

During my two visits with Gundran, most passersby didn't even acknowledge him. But he's so focused, he rarely has time to see the responses anyway. Honestly, it's a victory if you can even provoke a head turn from commuters scurrying to and from the trains. Watching Gundran perform for a non-captive crowd, I began to assign imaginary values for their responses: a glance = $1, a smile = $3, a stare lasting longer than three seconds = $5, a double take = $10, an earbud removal = $20. These little triumphs barely register with Gundran, who mostly seems engrossed by his own fingerings. He's a rather austere figure who wears the same basic black clothing from Converse sneakers to loose beanie both times we hang out.

Before he starts every busking adventure, Gundran scatters a few bills and coins inside his guitar case, because it seems to attract more money. He hooks up his instrument to a tiny Pignose amp and expresses whatever comes to mind for an hour or two. (Technically, amps are not allowed in the station, but as long as the playing doesn't drown out the announcements, security may let it slide.)

"The immediacy and unpredictability of performing in public places has always appealed to me," Gundran says. "Then a few years ago, I kinda rediscovered free improvised music and really dove into stuff coming out of China and Japan, where there's a strong tradition of playing in the streets, in unusual environments, and in nature. It has the kind of spiritual and absurdist vibe that I can't resist."

On a recent Thursday evening, a young man stops by and says, "You sound great," but doesn't tip. A bit later, a 60ish woman tosses some singles Gundran's way and her son asks if he wants his leftovers. Gundran politely declines. Shortly thereafter, a young guy flashes devil horns at Gundran. After that, a male friend approaches Gundran, scratches his back, and gives him some singles. Overall, not a bad outing.

The following Tuesday night is slower, unfortunately. The only person to donate is a hip-looking young woman with neon-green hair who drops a couple of crumpled bills in Gundran's case.

For an experiment, I ask Gundran if he knows any Jimi Hendrix tunes, which perhaps will prompt more donations. He says he can bust out riffs from a few songs, so he finesses the main part from "Voodoo Child (Slight Return)," but the famous blues-rock motif fails to generate any cash. Tough crowd! The real trouble with modern-day busking is that around 90 percent of Seattle pedestrians are already listening to music on their mobile devices.

Gundran says he usually shies away from really abstract stuff—but late in his Tuesday session, he starts to beat his plectrum against the strings in a staccato pattern, does some pick runs, and plucks some supremely odd chords near the headstock. One passerby looks at him with a befuddled expression, but the weird passage largely didn't seem to faze anyone else.

Another way Gundran differs from most buskers is that he's not trying to be an ingratiating entertainer. "I try to become part of the environment. I like the atmosphere. Aggressive buskers intimidate and repel me." He relates how a fellow musician tried to convince him to play the tourist-laden pier, but that sounded too stressful to Gundran. There's a purity to what he does that's refreshing.

"The unknown excites me, so I just show up and try to let it control me," Gundran says. "I'm influenced by so many different styles of music, it almost doesn't make sense, so I like to explore the connections between them. I would get frustrated if I couldn't move in different directions."

I ask Gundran if anyone's ever said to him, "Why is a white guy playing the blues?" without realizing he's part Asian. Nevertheless, he says he's long feared that question, but he's loved the blues since he was very young.

"Just recently at the station," he says, "a cool drummer from Jamaica named Junior said to me over and over, 'You're badass as 'ell, mon!' He asked about my race, and when I told him I'm half-white and half-Japanese, he was incredulous. I don't know what to make of that exactly, but I was flattered to be considered badass as hell by someone who seemed to be an authority on that."

So what's the best thing about busking for a lonely guitar wizard? "The movement and energy of the river of people penetrate my moods. I get handshakes, hugs, nods, smiles, compliments, and candy, and I take it all with me when I go."