By Day, Sun Studio Draws Tourists. At Night, Musicians Lay Down Tracks.

The historic room in Memphis has a thriving after-hours life, and generations of players come to capture a bit of the magic where rock ’n’ roll took shape.

The day’s last batch of tourists filed out of an exhibition space and entered a room overflowing with the sound of Johnny Cash’s “Cry! Cry! Cry!”

They’d spent the late afternoon soaking up stories about this small space with an outsize weight — Sun Studio, in Memphis, Tenn. — where the nascent sound of rock ’n’ roll took shape in the mid-1950s. It’s where Elvis Presley became Elvis and Sun Records made household names of Cash, Carl Perkins, Jerry Lee Lewis and others. It happened between the same well-worn acoustic tiles that still line the studio walls and its rolling, wavelike ceiling, and on top of the same linoleum where a hand-taped “X” marks the spot where Sun vocalists once stood.

The visitors took turns with a nonfunctional but studio-original Shure 55-series microphone, made available under two conditions: no stealing it and no kissing it. They settled for photos instead before exiting into the hot, late-July evening.

Then, almost as soon as the front entrance was locked, the back door opened and the local indie-rock band Blvck Hippie began to trundle in with gear.

The no-kissy mic was swapped for a working one and cables were threaded across the studio floor in an electric web, as the drummer screwed down cymbals and riffs rang from warming fingers on two guitars and a bass.

Before long a room intended to keep alive the memory of old songs had transformed, and was wired to capture new ones.