The growing popularity of artists like Feist and Iron & Wine -- what some are calling a folk revival movement -- has carried two inexorable promises: first, that aspiring independent artists with country, bluegrass, or folk sensibilities would once again claim their fair share of the music business, and second, that anyone who writes songs and owns a four-track can cut a record and start touring. Last night, a cozy Montreal audience glimpsed both ends of the spectrum.