San Marcos — Situated comfortably behind the counter on a lazy Monday morning, Greg Ellis decides it’s time for some tunes. The Sundance Records owner flips on a CD player, and the sounds of Grammy-winning bluegrass singer Tim O’ Brien’s new album “Chicken and Egg” drift through the speakers.

A few minutes pass before the first customer walks through the door.

“Hey Man! How ya doin’?” Ellis says to the obviously-familiar customer.

A minute later, a student scoots his bicycle in the doors of the record store and heads straight to the CD bins across the room. Ellis offers the same greeting to him. Tim O’Brien’s banjo rambles on in the background.

Three decades have passed, and in that time the entire music industry has turned upside down. But Sundance Records remains the same friendly neighborhood music shop it has always been.

“I always say we’re not selling music so much as we’re selling the experience and customer service,” Ellis said. “If you come in (to Sundance) a few times, we’re going to know what you like, you know? Then we can start directing you to stuff that we like that might fit in with that, or at least play it for you. And I think that people keep coming back.”

The locally-owned record store is celebrating 33 1/3 years of being open this month, and will mark the occasion at 6 p.m. tonight when Ray Wylie Hubbard — a regular customer at Sundance — performs an acoustic set inside the store. Beverages and pizza will also be served.

The store, first opened on the square by Bobby and Nancy Barnard in May of 1977, is a wall-to-wall gallery of popular American music from the 50s and beyond. There’s layers upon layers of artist posters, promotional cardboard cut outs of the Beach Boys and George Strait, newspaper clippings from the day Elvis died, and even a framed photo of cult hero Townes Van Zandt behind the counter.

Then there’s the music: Thousands and thousands of vinyl titles, both discount and collectible, CDs and an ongoing focus on local up-and-coming artists.

And in the digital age that’s arrived, stores like this are a precious few.

“Most kids in the 21st Century have never been in a store that looks like this. They’ve never experienced what a music store is like,” Ellis said. “At best, they’ve been to a chain where there’s a few racks in the middle of the store and a couple of disinterested clerks that have no idea what they’ve got.”

Ellis, who grew up working in record stores, first moved to San Marcos in 1982 to finish school at then-Southwest Texas State. He quickly became a regular customer at Sundance, stopping by in the evenings to visit with Bobby about the industry.

“He and I really hit it off. It turned out we had both started in the record business at the same time, and we both worked for the same company, Budget Tapes,” Ellis said.

By January of 1984, the store was really growing, moving to a new location on the square. Ellis helped the Barnards move the merchandise, and about a month later they offered him a job.

“I said sure, ‘sounds great,’” Ellis said. “ That semester I got my degree in journalism and had an internship at an advertising agency, and I was pretty sure I would parlay that into a full time job. I graduated in May, and in June Nancy asked if I would like to work full time at the store, basically as a store manager... It took about 10 minutes for me to make up my mind. I was really not enjoying what I was doing at the advertising agency, and I was really falling in love with San Marcos at that point.”

Ellis stayed at Sundance until 1990, when he was offered a job in Houston with the music distributor the store was buying its product from. He spent the next 15 or so years working in marketing and promotion for major and independent labels in the Houston area, before the economics of the music industry forced them out.

Last year, he got word that Bobby and Nancy were both looking to retire.

“I called Bobby and said ‘would you like me to come in and take over for you?’” Ellis said.

The timing was perfect, and Ellis says he often sees some of the same people who were regular customers 20 years ago. And while the climate of the industry and mediums for which music is consumed has changed, Ellis says the store looks to remain a cornerstone in the San Marcos music scene.

“I believe we have a legitimate chance against things like iTunes and stuff like that, where you pay for nothing. You get the content, and you get a flash of the album cover when it comes on your iPod, and that’s it.”

The store’s also benefited from an unexpected resurgence in vinyl among younger customers in recent years.

“The whole experience with vinyl is different; you hold it in your hands, it’s big, you read it. It opens up and there’s art work... We’ve carried vinyl since the beginning, but lately we’ve really re-established our vinyl collection.”

And if customers buy something or not, Ellis is just glad to see ‘em walking around the store.

“Even if they’re not buying CDs, they hear the music, they talk about it and it connects with them in some way. Our focus is making sure that when somebody walks through the door, they have an experience they can’t have otherwise,” Ellis said.