Though primarily associated with the classic Motown sound, soul music comes in all shapes and sizes.

At the 2008 South by Southwest (SXSW) festival in Austin last week, it came from eastern England, the backwoods of Wisconsin, the suburbs of Sacramento, and the western shores of Wales.

Alice Russell, Bon Iver's Justin Vernon, Darondo, and Duffy all put their own unique stamp on the genre through the course of the week with dazzling depth and feeling.

Russell and Darondo had the most obvious connection to classic soul, with the former drawing on jazz and the UK's Northern Soul movement and the latter delivering what can best be described as a James Brown-meets-Al Green tour de force.

Bon Iver took a decidedly different approach, infusing atmospheric acoustic folk with haunting heartache, and Duffy channeled Dusty Springfield in a spot-on set Friday afternoon, her first ever in the US.

Here's a brief recap, in reverse order of appearance:

Darondo

There have been dozens of remarkable funk and soul frontmen over the years, but very few have had the ability to make just about anything sound funky. Darondo, a 60-something singer from Northern California whose terribly brief music career in the 1970s has resulted in an almost mythological backstory among crate diggers, is one of those people.

The guy could riff on the merits of flossing--something which his dearth likely doesn't require him to spend much time doing--and still keep the crowd rapt and the dance floor filled.

Darondo played a brief set Friday afternoon and a longer one Saturday night at the showcase of Ubiquity Records, which rereleased some of Darondo's incredible recordings in 2006 and plans to put out a new Darondo album later this year.

For both sets, Darondo was backed by an ultratight band of Bay Area stalwarts, led by emerging talent Nino Moschella. The tracks moved between the celebratory--"How I Got Over" subtly fed the myth that Darondo used to be a pimp--and the commanding, particularly on the charged "Let My People Go."

Darondo stalked the stage like a cat, dropping down for lightning-quick splits and flirted with the ladies on the lascivious "Legs."

He proved perfectly worthy of all the hype heaped on him by record collectors and bloggers over the years, leading some to wonder what might have been had he not called it quits some 30 years ago.

Duffy

Although their takes on retro soul are considerably different, it was hard not to think of Amy Winehouse when Welsh singer Duffy took the stage Friday afternoon at The Parish for the Mercury Records showcase.

Exactly one year earlier and just one block away, a bee-hived and tattooed UK chanteuse strutted on stage for the first time in the US and put on a remarkable show. She would go on to garner both critical acclaim and commercial success, snagging five Grammy Awards along the way, despite a shockingly public drug-fueled downward spiral in the latter half of 2007.

Duffy's sound is significantly more polished and less than funky than that of Winehouse, packed with more class than sass. Complete with bent-elbow hand motions and limited movement on stage, Duffy seemed a bit packaged--but her voice tore any doubts to shreds.

The singer put on a sparkling 20-minute set that would have Springfield, her most obvious sonic ancestor, quite proud. Kicking off with the sensational "Rockferry" and closing with the Spectorized-"Mercy," Duffy showed a set of pipes that belied her petite blonde frame.

Her debut album, Rockferry, is currently No. 1 in the UK, and she seems destined for Winehouse-level success, if not excess.

Bon Iver

Nary has a soul man emerged from Eau Claire, Wisconsin, and a cabin in the cheesehead state's backwoods isn't a typical place from whence a record as soulful as Bon Iver's For Emma, Forever Ago would originate.

That said, the sound that Bon Iver (pronounced "bohn ee-vair," a tweak on the French term for "good winter") singer and songwriter Justin Vernon has come up with is indisputably soulful. Joined by a drummer and a second guitarist at a show at the Mohawk Patio, Vernon mixed his magnificent falsetto with a lo-fi folk sound that continually pushed the envelope.

The set kicked off with "Flume," the opening track on the album Vernon crafted by himself in a remote cabin in his home state following the breakup of his previous band, DeYarmond Edison.

"The Wolves" followed, with Vernon asking the crowd for help in the song's latter half, hoping to "fill the street with sound. Just try it or it will be totally lame, and you won't have a good time," he joked.

The packed house came through, joining the band on the refrain, "What might've been lost..." over and over, turning an already incredibly song into a come-to-Jesus moment for some. After about two minutes, the melancholic-yet-beautiful refrain melted into a cacophonous sea of wails and distorted guitar. It was utterly incredible.

Alice Russell

Best known in the US for her work with Quantic/Will Holland and his ferocious Quantic Soul Orchestra, Russell is set to break out, particularly with the retro-soul revival sparked by the likes of Winehouse, Mark Ronson, and Sharon Jones & the Dap Kings.

Backed by a tight band of players from the UK and San Francisco, Russell was a one-woman party starter at the Elephant Room. She moved between originals, Quantic tracks, and covers with ease.

Like both Duffy and Winehouse, Russell's looks and voice are a bit incongruous. But she has an even wider vocal range than the other two.

The highlight was the bombastic closer, a cover of the White Stripes' "Seven Nation Army," which Russell and guitarist TM Juke turned into a foot-stomping funk romp.