Deep within the high-security Iron Mountain storage facility in Hollywood, where nearly every doorway except for the restroom is protected by a security-card swipe lock, sits the Grammy Museum's permanent collection of pop music artifacts, recordings and memorabilia.

Hundreds of 10-inch 78 rpm discs - some from Thomas Edison's record label - reside in archival boxes on 20-foot-long metal shelves, near antique radios and phonograph players, musical instruments, posters and some celebrity fashion items stored out of sight in sturdy garment bags.

Vintage synthesizers in their original cases take up a shelf right below three distinctively different accordions, an instrument Mark Twain famously dubbed "the stomach Steinway."

The Grammy Museum may have opened a little less than four years ago in downtown's L.A. Live entertainment complex, but it's already looking at myriad new ways to store and exhibit its extensive collection of music history.

"People offer to donate things, but until we had someplace to properly store and preserve them, we've had to turn a lot of those offers down," executive director Robert Santelli said last Friday during a walk-through of the museum's growing archive.

"We have to be able to safely store the items, insure them - and be sure we can make them accessible to the public at some point, because we are an educational museum," he said. "We're working without an acquisition budget, so we have to rely on donations."

Grammy Museum assistant curator Ali Stuebner slipped on a pair of white cotton gloves to peek under the lid of a 4-foot-tall 1920s-vintage Edison phonograph resting against one of the storage space's bunker-like concrete walls, and to show a visitor one of two old piano accordions donated by squeeze-box virtuoso Ernie Felice. She later riffled through a couple of large boxes, each holding perhaps thousands of 5-by-7-inch white notecards collected from one of Yoko Ono's wishing trees.

It's gems like these that caused the museum to enter into a partnership with Iron Mountain about 18 months ago, the company providing the storage space about six months later.

The Grammy Museum is a repository of about 900 air-conditioned square feet, compact compared with some of Iron Mountain's 800 other entertainment-world clients, whose holdings fill a 10,000-square-foot floor of the 14-story building.

All the major record companies store master recordings made over the last 90 years here, said Jeff Anthony, Iron Mountain senior vice president of entertainment services. These recordings have increasingly become a part of revenue-generating plans as new music has become ever more challenging to break.

The Grammy Museum's own recorded history is stored at Iron Mountain but in digital form, an archive of more than 200 performances and live interviews recorded at the museum since it opened December 2008. The audio-visual archive at the museum opens to the public on Wednesday.

"We've captured more than 800 songs played and performed in the museum, and we're at about 225 artists we've interviewed for these living histories," Santelli said. "Each of these are pieces that help to tell a greater story."