NANCY COVEY had a profound influence on my musical youth, although I was not able to put a face and name to my teenage experiences until a couple of weeks ago.

She booked the concerts at McCabe’s Guitar Shop from 1974 to 1984, a golden era for the Santa Monica shop that has been presenting intimate shows in its back room on weekends for nearly 30 years. Covey ran the venue at a time when my musical tastes were being shaped, in this case largely by folk-based musicians whose music had no correlation to anything being played on the radio or in any other venue in Los Angeles. McCabe’s was a slice of heaven.

The shop turns 50 this year, an anniversary that will be celebrated Thursday at UCLA’s Royce Hall on a bill featuring Jackson Browne, Richard Thompson, David Lindley, Jennifer Warnes, Peter Rowan, Peter Case and many more. Covey is among the organizers, her goal being “to show a thread among the performers” on the bill.

McCabe’s, more than any other source, was my portal for the discovery of new music during my high school years. The shows I saw there were by musicians who excelled at their craft, people like Mary McCaslin and Jim Ringer, the David Grisman Quartet, the Country Gentleman. Not household names, but performers capable of showing a young person interested in music a direction other than the mainstream, which at the time was a muddle of glam rock, the Eagles and their spawn, adult pop and early disco.

It intrigued me that this source of my musical education would celebrate its first half-century amid the proliferation of countless websites touting their abilities to be portals of discovery. MySpace Music unveiled its rebuilt facade last week; AOL’s redesigned Spinner site was relaunched Monday; LP33.tv, a curated site for indie bands from the creators of music industry database http://www.themidb.com, will open Thursday touting indie acts across several genres.

Perhaps it’s a generational reaction, but the websites positioning themselves as places to find new music — from the iTunes store to the sites that operate as clearinghouses — appear severely limited regardless of how big their databases may be.

Commerce-driven/promotional music sites work well when the user knows what they are seeking — and no website has been able to crack that conundrum. The web — and this extends beyond music — promotes the concept of liking what you know, possibly enhancing the fan experience and connecting like-minded individuals.

THE MCCABE’S PARADIGM — and this spreads across the country in the venues, record stores and radio stations that develop a level of trust between presenter and consumer — is also community-based, one that has remained in place for decades. In recent years, celebrations of live music venues are almost always for ones that have closed, CBGB and the Bottom Line in New York for example. Those venues, though, were not so much vital members of a musical community but marquees for memories.

You remember what you heard at McCabe’s: John McEuen of the Nitty Gritty Dirt Band making his solo debut, wearing two different-colored socks. Toulouse Engelhardt playing an electric guitar in this acoustic mecca. The Boys of the Lough explaining what a bodhran was. Norman Blake on guitar with wife Nancy on cello doing a set that would become a live album. Jorma Kaukonen playing pre-WWII music. Browne celebrating a Grammy win in honor of the late Warren Zevon.

There’s something about bonding in a small space that Dave Alvin once referred to as “too quiet”; he made the comment while tuning a guitar amid dead silence. That apparently can be unnerving, if not intimidating.

Covey limits her list of big discoveries — besides her husband Richard Thompson — to two: John Hiatt, who first played McCabe’s opening for John Lee Hooker, and Vince Gill, who played bluegrass as a kid and “had the confidence” you rarely see.

The beauty of the lineup for Thursday night is the gathering of performers who have played its stage, demonstrating how vital the McCabe’s stage remains and how some institutions adapt to the times by staying the course.