There are a few magical studios with such amazing sound that they have become sort of sonic temples for musicians who dream of making musical pilgrimages to them. There’s Hitsville U.S.A. in Detroit, home to the Motown sound. There’s FAME Studios in Muscle Shoals, Alabama where artists like Wilson Picket and Otis Redding honed the 60’s southern soul sound.

And then there’s Capitol Records studios in Los Angeles. Housed in the iconic circular building on Hollywood and Vine, it’s uniquely famous as much for what it looks like on the outside, as what’s been created on the inside.

Designed in 1956, the building was actually not meant to resemble a stack of records but well…happy coincidence. A red light, like a beacon, atop the tower flashes “Hollywood” in morse code. And inside the building artists like Frank Sinatra, Nat King Cole, The Beach Boys, The Beastie Boys and so many more have laid down countless hits.

But what gives Capitol Studios its great sound qualities? Why do artists dream of recording there? At Capitol, much of this magic is attributed to a curious design element that was created by Les Paul, the guitarist and inventor of the famous Gibson Les Paul guitar. Paul was commissioned to give the studios reverb, the sonic quality of echo and delay, or reverberation. Today, musicians use reverb pedals attached to amps to easily achieve this, but in the 1950’s it apparently wasn’t so easy and thus was Paul’s challenge.

To create reverb, Les Paul built a series of eight cavernous trapezoidal echo chambers dug 30 feet below the Capitol Records building. The sparse concrete chambers, each with there own unique characteristics, have speakers on one side and microphones on the other. Sound engineers working in the studios above can pipe audio into the reverb chambers and re-record the sound, adding as much as a five-second delay, giving singers a booming vocal quality that makes it sound more like the track was recorded in a cathedral, not a sound studio in L.A. The difference is huge.

You can fast forward to the 6:30 minute mark in this American Roots segment to hear recordings with and without the echo chamber effect but really, listen to the whole thing. You can also see YouTube clips of the reverb chambers here and here. A look inside the building as it looks now can be found here.

Now there are plans to develop the area around the Capitol Records building. Some are concerned that could threaten the reverb chambers, Here’s hoping some things don’t ever change. -JP