Twenty-five miles away, in suburban Monterey Park, a 16-year-old wunderkind was beginning to find his groove. After starting on guitar at six and switching to electric bass at nine, he’d begun taking lessons with Steppenwolf/Delaney & Bonnie bassist Fred Rivera. His teacher, Herb Mickman, was schooling him on electric, upright, piano, and jazz harmony, and it was Mickman who suggested they go see the Bill Evans Trio—at the Playboy Club. “I wasn’t even allowed to be there, but somehow he managed to spirit me into the place,” says Klein four decades later. “You can imagine a 16-year-old kid seeing Bill Evans and Eddie Gomez at the Playboy Club, with Playboy Bunnies walking around. I thought I had died and gone to heaven!”

That’d be a high point for any teenage jazz fan born in the ’50s, but Klein’s career hadn’t even begun. His broad palette and ear for pop allowed him to move smoothly from a promising late-’70s stint as a top-flight jazz sideman (Freddie Hubbard, Dianne Reeves) to a career as a versatile session ninja (Robbie Robertson, Bob Dylan, Wayne Shorter) with filmscoring skills (Grace of My Heart, Duets), capable of creating bass sub-hooks on huge ’80s hits (Don Henley’s “Boys of Summer” and Peter Gabriel’s “In Your Eyes”), as well as a fresh, contemporary approach to Joni Mitchell’s music after her celebrated string of albums featuring Jaco Pastorius.

It is as a producer and co-writer, however, that Klein has achieved his widest fame. His resumé is especially notable for the long list of great female singer/songwriters—including Tracy Chapman, Madeleine Peyroux, Shawn Colvin, Julia Fordham, Bonnie Raitt, and Holly Cole—with whom he’s worked. Over the years, Klein has developed a reputation for being relaxed, sensitive, and open to new ideas, qualities that certainly endeared him to Mitchell, who first hired him in 1982. They were married from 1982 to 1994, and Klein has played on, produced, or co-produced everything she’s done since the ’80s, nabbing Grammys for his contributions to 1995’s Turbulent Indigo, 2001’s Both Sides Now, Herbie Hancock’s 2008 masterwork River: The Joni Letters, and its follow-up, 2011’s The Imagine Project.

More than 40 years after he hit the scene, Klein’s Strange Cargo label gives him the freedom to work with handpicked artists such as Thomas Dybdahl, whose sexy, trippy, Klein-produced What’s Left Is Forever hit shelves last year. When the mood strikes him, he reaches for a sunburst ’62 Jazz Bass, a Gretsch Country Gentleman, or his longtime favorite, a Music Man StingRay 5-string, but producing is what he loves most these days.

He’s done three Grammy-nominated albums with his wife, the accomplished Brazilian songstress/producer Luciana Souza—“a wicked demon of a musician”—and is working on a fourth. Nominated for a Producer of the Year Grammy in 2009 for his work with Melody Gardot, Klein has much to look forward to, including projects with J.D. Souther and Liz Wright, another record with Gardot, and “an ambitious project” with Chinese piano virtuoso Lang Lang. What’s the most crucial advice he could give after all these years of high-profile collaborations and successes? “Hold on to your humility, and seek out great teachers. That would be at the top of my list.”

You took lessons with Fred Rivera and Herb Mickman, but did you have other teachers?
Those were my two first teachers, and then all through junior high and high school I went to USC Community Schools, now the Colburn School, where they had great teachers and guest lecturers such as Michael Tilson Thomas. I also took private composition classes with a guy named Wayne Bischoff, a Mr. Holland’s Opus-type character, in seventh grade, and I studied classical arco technique with John Schiavo of the L.A. Philharmonic. I was really lucky all my life in finding the right teachers.

How relevant to your career were those years of studying theory and harmony?
All the things you absorb, whether it be a Beethoven symphony or a song you hear on the radio—all of it ends up informing your musical instincts. Early on, it may have seemed like all that disparate information had no effect on what I played intuitively, but eventually, it affected how I built bass lines and how I saw bass fitting into the design of a given track.

Everything in our world now is so abbreviated, moving at such an incredibly fast rate, people forget that apprenticeship and studying and focusing on the basic building blocks of playing and writing music are so important. I’m happy to rant on that whenever possible.

How did your time with Joni Mitchell affect your knowledge of harmony?
Profoundly. She crafted a sense of harmony for herself by virtue of the tunings she developed, all because she just didn’t have the hand strength to finger chords in the usual way. I ended up using those guitar tunings myself to write with, so yes, she strongly influenced my sense of harmony and composition.

What’s your perspective on Jaco’s work with Joni?
Before me, guys like Max Bennett—and even earlier, Stephen Stills—had played on her records. Joni was ready to work with someone who played in a way where the bass wasn’t down at the bottom of the track. Jaco was her liberator in that respect.

You began working with Joni just after her last album with Jaco. How was that?
Jaco was functioning pretty much exclusively as a melodic counterpoint to Joni, and by the time I began working with her, she wanted the bass to have a greater part in holding down the groove. At the same time, she also didn’t want anything that resembled a conventional approach. So I was searching for my own way of approaching both her music and the role of the bass.

Of all the work you’ve done together, what stands out?
Different tracks from all the records pop out from time to time. I like so many things, but Night Ride Home [1991] was a wonderful record to make, and I’m really proud of the bass work on there. I was asked to contribute to a book about Joni [2013’s Gathered Light: The Poetry of Joni Mitchell’s Songs], and I chose to write about “Chinese Café/Unchained Melody” [from Wild Things Run Fast, 1982]. There’s something so profound about that track— it makes me cry every time I hear it.

Did you get to hang with Jaco?
Yes. As a person, he was such a walking idiosyncrasy. He was so confident and arrogant, but there was a part of his spirit that was innocent and had such a fun edge that I would never hold that against him.

You walk into a session and hear a track for the first time. What goes through your mind?
I hear things that tie into the melody, the chord structure, and the way the song is designed. I hear these repetitive things, and I’m sure the reason I hear them is that I’ve absorbed so many great bass parts by other bass players.

Do you think bass players are naturally suited to being producers?
We sit at the intersection of groove, harmony, and melody, and spending years providing the right kind of structure can prepare one to have a vision of how the landscape of a track should be built. But being a producer is a very complex job that changes with every record and every artist.

When you produce at the highest level, you become just another person in the room who’s directing, opening doors, and shedding light on things. Everyone leaves the studio thinking, Wow, I just played better than I’ve ever played. They don’t go home thinking, That guy is a great producer. When you’re really doing your job, you almost disappear.

How did you apply that to Thomas Dybdahl?
He had already built a substantial career and made some great records on his own, so I wanted to explore parts of himself he hadn’t really explored. A lot of things we did were based on germs of things he’d done in prior projects.

Did you begin the sessions with strong production ideas?
Early on, Thomas asked me what production techniques I was planning to use, and the only thing I could say was, I don’t know. But I told him that a lot of it was inside him already. The last thing I wanted to do was to come in with a bucket of tricks and redesign the way he did everything.

Do you usually play on sessions you produce?
I go back and forth. Sometimes, it’s just too many things to do at the same time, so I have some great bass players who are also very patient with me suggesting things. David Piltch played on Thomas’ record; I work with him quite a bit. I’ve been a fan of Lee Sklar since I was a kid, and I love using him on records, too.

How did it feel to “replace” Ray Brown on The Merv Griffin Show?
Right when David Letterman’s show became the hot thing, Merv wanted to “young up” the band, so Ray Brown was one of the first people to leave. They asked me to come and play, and it was pretty comical, in my mind, that I was going to replace Ray Brown. But it was actually pretty fun, and it was a good experience to be able to play in so many different contexts within a short amount of time. One day I’d have to play with Buddy Rich, the next day with Steve Lawrence and Eydie Gormé, and then the next day, B.B. King.

How do you split your time between upright and electric?
If someone calls me to play on a record these days, first of all, it’s difficult for me to do schedule-wise, but I’m more apt to do it on electric. I just don’t get a chance to put in enough time on the upright where I really feel good playing it on a record I’m producing.

Is it true that you had to convince Walter Becker to play bass on his own Circus Money?
Yes! I produced it and Walter wanted me to play on it, but I felt adamant that he play on it. People don’t know—he’s serious as a bass player! He’s got such a deep groove, and the combination of him and [drummer] Keith Carlock on that record was just amazing.

Do you go on the road often?
Not much these days. In fact, Walter was asking if I wanted to do the Steely Dan gig for a tour a little ways back. As much as I would love to, my time right now is better spent making records, and I’ve got a five-year-old son, so I want to stay home as much as I can.

What’s your take on creating a long-term career in the music business?
Joni always used to say that the quickest way to kill your career was to have a hit, and maybe that’s true. I certainly like success, but I don’t make my decisions based on what I think is going to be a hit. I try to make records that will stand the test of time and change people as they listen to them. I’ve managed to keep a fairly pure motivation, and there’s something to be said for the role that plays in one’s longevity in the music business.