Somewhere between Atlanta and Norfolk, Va., a band from Chicago named Bound Stems was in its van, barreling along a rainy highway on the way to the 26th annual CMJ Music Marathon, which starts today. Bound Stems are one of more than 1,000 bands appearing over the next five nights in more than 60 clubs around Manhattan and Brooklyn, hoping that half an hour onstage could change their lives.

''Every band in the world is coming,'' said Bound Stems' main songwriter, Bobby Gallivan, through a faltering cellphone. ''I've heard of bands that made their big splash at CMJ. Obviously that would be awesome if it happened to us.''

The CMJ Music Marathon, the music-business convention devoted to independent musicians, was started by the magazine that monitors college radio and was initially called College Media Journal. As the big-time music business struggles to hold on, the small-time music business -- self-made bands, independent labels, college radio stations, music Web sites -- is more active than ever.

''With the anarchy and confusion and volatility out there,'' said Bobby Haber, chief executive of CMJ, ''there is so much concern, not only for one's own job but for where the industry is going. People know they're going to get their networking done here, and maybe they'll get some answers.''

Uncertainty has been good for CMJ, which expects as many as 12,000 participants, who have signed up to attend its daytime panel discussions and nighttime shows. About 70 percent are not college students, but either musicians or the music-business personnel who pay the professional rate, up to $495 per laminated pass. The music marathon grows this year from four days to five, and it's possible, Mr. Haber said, that in the future it could stretch to a full week.

The do-it-yourself strategies of punk and hip-hop work even better in the Internet era, when musicians no longer need anyone else to manufacture or distribute their recordings -- just a Web page and a click or two -- and a record company can be a printer and a CD burner. ''In this environment,'' Mr. Haber said, ''the indies can be efficient, productive, successful and actually in the black, which doesn't happen too often in the major labels today.''

Meanwhile, Web sites like MySpace and Purevolume ( make more music available than any battalion of listeners could ever sort through. ''Everybody's got access now, so it's a little less exclusive,'' said Matt McDonald, CMJ's showcase director. ''It takes away some of the tastemaker thing. But it's better for the bands.''

Yet for musicians trying to turn a hobby into a career, hitting the road to perform live is still the time-tested way to be noticed, especially if there's some Internet buzz to build anticipation.

CMJ promises musicians practical help by day, with panel discussions on everything from constructing a Web page to pitching songs for television. And at CMJ showcases and an increasing number of unofficial parties, day and night, the marathon holds out hope to musicians that they will play for an audience that includes the right connection. In a world of downloads, physical presence can still make a difference. And it's easier to sell T-shirts in person after the set.

Making their way to CMJ, Bound Stems have been on the kind of tour that defines the indie-rock life: carrying their own equipment, sharing bills with slightly more experienced bands, headlining clubs that are packed in some cities and nearly empty in others.

The five-member band plays brisk, tightly wound guitar rock that works through pattern after pattern behind the fractured storytelling of Mr. Gallivan's lyrics. There are touches of the band's fellow Chicagoans Wilco and Tortoise in the music, but Bound Stems have their own impatient timing and oblique revelations. ''You can learn without the system,'' a song called ''Western Biographic'' declares. ''Go ahead, because even a dark horse wins.''

Bound Stems got together in 2002 and finished recording their debut album, ''Appreciation Night'' (Flameshovel), last year, but waited to release it until this September so they could tour nationwide. They quit their day jobs this summer. ''We've been thrown to the wolves,'' Mr. Gallivan said.

After Norfolk, the band had more gigs en route -- in Washington and Philadelphia -- on the way to playing five shows in four days during the marathon: four semiprivate parties and then an official CMJ showcase on Friday night at 10:45 at the Knitting Factory Tap Bar. Mr. Gallivan thought the band would be paid for one of the party gigs, but he wasn't sure.

A friend will lend the group a two-bedroom apartment in Brooklyn. To protect their equipment on the New York streets, band members will take turns sleeping in the van.

They aren't expecting instant rock stardom. ''We want to be able to play our songs and never grow up,'' Mr. Gallivan said, laughing. ''The moment it becomes work or it feels like it's a job, it defeats the purpose of it. The goal is to be able to live off of it. We'd like to be able to pay the rent.''

Photo: Bobby Gallivan and Janie Porche of the Chicago band Bound Stems, which is playing five shows in four days at CMJ Music Marathon. (Photo by Michael Alan Goldberg)