Who's your best friend?

She played bass on 10,000 songs, including the most-played track of the twentieth century. She was paid $55 per session. Her name never appeared on the albums.

Gold Star Studios, Los Angeles, 1964. A woman in a cardigan walks past the receptionist, a Fender Precision bass in her hand like a briefcase. She doesn’t sign autographs. She signs a timesheet.

Her name is Carol Kaye. In three hours, she will record what will become the most-played track of the twentieth century. She’ll pocket fifty-five dollars and head to another studio, on the other side of town, for the next session.

The record label will never put her name on the album.

Between 1957 and 1973, Carol Kaye took part in roughly 10,000 recording sessions. Not as the featured artist, not as a guest, but as a hired hand. She was part of an anonymous collective nicknamed The Wrecking Crew—elite studio musicians who actually played the instruments on your favorite records while the famous bands posed for promotional photos.

The work was relentless. Three albums before the day was over. Stale coffee in paper cups. No rehearsal. The charts arrived minutes before the tape rolled. If you couldn’t read a chart and nail the take in two tries, you didn’t get called for the next session.

Carol could do it on the first try.

She started playing guitar in grimy bars at fourteen because her family couldn’t pay the electric bill. Music wasn’t a romantic dream for her. It was survival. It was a job—factory work with better acoustics and lower pay.

But she was faster and sharper than almost everyone else. She corrected charts in pencil while the producer was still explaining what he wanted. In one session in 1968, she told a famous producer his arrangement sounded like a dying dog. She chose her own line. They kept her version.

That descending bass line that drives the Beach Boys’ “Wouldn’t It Be Nice”? Carol Kaye. The propulsive groove of “These Boots Are Made for Walkin’”? Carol Kaye. The acoustic-guitar intro to “La Bamba”? Carol Kaye. The iconic theme from Mission: Impossible? Carol Kaye.

She invented techniques on the spot, out of sheer necessity. When the bass sound was too muddy for AM radio, she stuck felt under the strings and used a hard pick instead of her fingers. The tone cut through the static like a blade. It became the sonic signature that defined 1960s pop.

Bassists spent years—decades—trying to crack the secret of the Beach Boys’ gear to get that sound. They were studying the wrong people. They should have been studying Carol.

She received no royalties. No residuals. No gold-record ceremony. No credit on the album sleeves. When “You’ve Lost That Lovin’ Feelin’” hit number one, Carol was already back in a studio cutting a soap jingle.

The biggest bands mimed her bass lines on TV variety shows. New York marketing departments decided a mom in classic clothes didn’t fit the rebellious-youth image they were selling. So they simply left her name off the album credits.

For thirty years, almost no one cared. The truth only began to surface in the late 1990s, when music researchers found the same union contract numbers on thousands of hit records. The very documents meant to preserve studio musicians’ anonymity betrayed them.

Think about it. Every time you heard “Good Vibrations,” “River Deep – Mountain High,” the Righteous Brothers, Nancy Sinatra, or Sonny and Cher, you were hearing Carol Kaye. She composed the soundtrack of an entire generation’s youth.

And yet the records still say nothing. She’s now over eighty. She wrote instructional books. She trained countless bassists. She is finally starting to be recognized by music historians who uncovered the truth about The Wrecking Crew.

But she never got what she deserved: her name on those albums. Credit for the music that defined an era. Recognition that those bass lines everyone associates with the “Beach Boys” were, in fact, Carol Kaye’s.

Fifty-five dollars a session. Ten thousand sessions. The most-played track of the twentieth century.