One picture shows Frank Sinatra crooning into a sleek, silver microphone, his fedora tipped back. In another, Nat ing Cole sits in front of a music stand in a crisp, white V-neck sweater.

Both were taken only a few feet away, a half-century ago, in the wood and glass studios of Capitol Records’ famed cylindrical tower in Hollywood – familiar to tourists from around the globe as resembling a giant stack of vinyl records.

In this age of mp3s, digital home recording and compressed and condensed tunes, the Capitol Studios remain a rare gem – a legendary yet working homage to high-quality sound, from Sinatra to The Beach Boys to Tim McGraw.”It’s not a historical monument to itself, it’s a contemporary studio,” said engineer Jim Scott, who recently recorded Dido with a 30 piece orchestra at Capitol.

But the large, three-room facility and its fabled subterranean echo chambers – whose sound, experts say, cannot be recreated – may soon be picking up some bad vibrations from an adjacent 16-story condominium and office project, part of downtown Hollywood’s ambitious revitalization effort.

Sound engineers fear noise from the construction site, as well as from traffic that would eventually use the project’s underground parking garage, will ruin the delicate aural qualities of the echo chambers.

A Los Angeles City Council committee recently denied an appeal by Capitol parent EMI Music North America and recommended approval of the project, contingent on a series of additional measures – including construction walls and a foam barrier – to mitigate potential sound issues. Capitol had worked out the measures with developer Second Street Ventures as a backup plan, though still opposes the project.

“Capitol Records’ executives are reluctant to keep open the recording studios and echo chambers if they run the risk of lawsuits from recording artists and their record labels,” EMI’s attorney John Whitaker said at the hearing.

David Jordon, co-owner of Second Street Ventures, said he felt confident that the measures would protect Capitol Studios’ signature sound.

“We have no desire to create any negativity toward Capitol Records,” he said. “Our design is to enhance and protect this iconic building and the area around it. From a personal standpoint, we wouldn’t want that kind of liability.”

Jordon maintains that his company is only looking to do loud excavation and demolition from 7 a.m. to 10 a.m. He also says there would be an emphasis on “open and constant communication” with Capitol, including an onsite attendant every day. Discussions continue regarding compensation to Capitol if recording sessions are affected, he said.

The full council is set to give a final vote on the proposal July 8 in a session that could attract the many music industry insiders who oppose the project – from engineers to The Recording Academy.

“Those echo chambers at Capitol should not ever be lost. That sound cannot be reproduced,” said engineer Geoff Emerick, who recorded the Beatles’ Sgt. Pepper’s Lonely Hearts Club Band and Revolver.

Musician and producer Jon Brion, who has recorded Kanye West and Fiona Apple, said he was upset over the issue.”There are very few specially-built studios left, and the chambers are the thing that make it special,” he said. “This is a rarified world, but we already lose too many things culturally. Should we listen to the people who have never recorded music, who say, ‘What’s the big deal about putting up a parking lot?,’ versus the engineers who are the canaries in the coal mine? This was the BEST thing of that era. People traveled here then, and still do.”

Sinatra recorded his seminal 1958 album Only the Lonely in the studios, using the echo chambers’ reverb to enhance his voice. Other famed musicians who have recorded there since the tower’s 1956 opening include Dean Martin, Natalie Cole, Ringo Starr, Paul McCartney, Diana Krall and James Taylor. Green Day recorded most of its Grammy-winning 2004 album American Idiot there.

The Oscar, Emmy and Grammy orchestras also use the studios, which can hold up to 75 musicians, as do the television shows “American Idol” and “Lost.”Today, about 90 percent of the artists who record there rent the facilities independently and are not connected with Capitol/EMI.

“To steal a quote from (Beatles engineer) Phil Ramone, ‘People just play better here,'” said Greg Parkin, Capitol Studios and Mastering’s senior director of operations.

Buried more than 25 feet below the Capitol tower’s parking lot, the studios’ trapezoidal-shaped echo chambers, built out of 10-inch thick concrete walls, were co-designed by famed sound innovator Les Paul, who pioneered the electric guitar and helped develop multitrack recording.

Artists sing or play into microphones in the studios and the sound is piped through wires in the walls down through a corridor and into the chambers, Parkin said. Speakers in the chambers bounce the sound to microphones on the other side, which pick up the music in stereo and then funnel it back to a mixing console in the studios. This provides a smooth delay of sound, or reverb, which can last up to five seconds. Underground isolation is necessary to establish purity of the sound.

“Loud noises are our enemy, that’s just the nature of the business,” Parkin said. “When you’re doing a very delicate string date, any interference can be a problem.”

He added that the chambers have never been replicated digitally – and that’s why artists still travel to Capitol from around the world.

“The Capitol Studios are part of Hollywood’s history, part of the Beach Boys’ history and part of my own history,” Brian Wilson said in a letter to the Los Angeles City Council. “I can’t emphasize enough how important it is that you do everything in your power to protect that history for generations of recording artists to come.”