Stevie Wonder's Music of My Mind is more important than it was necessarily transcendent, more representative of where he'd go than any real chart benchmark.

He'd taken the first tentative steps toward greatness on 1971's preceding Where I'm Coming From, producing the album himself while employing some embryonic synth work, striking up a musical conversation with future wife Syreeta Wright, and tackling more complex societal issues.

Those aren't just features of the following Music of My Mind. They define the album, providing a roadmap for every success that awaits Wonder during a period of sustained brilliance in the '70s.

He'd become enamored with a new multi-use synthesizer invented by Malcolm Cecil and Robert Margouleff while dealing with a post-Where I'm Coming From contract dispute with Motown. Introduced to Wonder by shared lawyer Johanan Vigoda, the duo brought the setup to Jimi Hendrix's Electric Lady Studios, where Wonder was working on his music while Vigoda continued negotiations with label head Barry Gordy.

Wonder's musical partnership with Cecil and Margouleff ultimately spanned four landmark albums, including Talking Book, Innervisions and Fulfillingness' First Finale. At this point, however, many critics had yet to embrace the synthesizer as a foundational musical tool. Wonder would, in no small way, change that.

But first, the 21-year-old had to get out of an onerous original contract with Motown Records. Originally billed as "Little" Stevie, Wonder released his debut LP a decade earlier. His deal called for a tiny 2 percent royalty rate on 90 percent of sales, but only after all recording expenses were recouped. Gordy also claimed another 25 percent of the total earnings for services as Wonder's manager.

Listen to Stevie Wonder's 'Love Having You Around'

Not that Wonder saw any of it. Because he was a minor, Wonder's earnings had been placed in a trust until he turned 21. He and his mother Lula Mae Hardaway were given a weekly stipend of just $2.50. Meanwhile, he'd already delivered seven Top 10 R&B smash albums to Motown and a slew of hit singles, including the Hot 100 chart-topping smash "Fingertips – Part 2."

"It wasn't just a question of him selling more than other people," Vigoda later argued. "It was that he was in a bigger league: He had the potential, musically, to be the heavyweight champion of the world."

Renegotiations were inevitable once Motown's prodigy became a legal adult – and no one was more aware of that than Wonder himself. "Now, just a minute: 'This "Little" stuff has got to stop," the then-16-year-old famously told Shelly Berger, who headed up Motown's offices on the West Coast. "I've been six feet tall for two years."

Still, the terms – and their implications – were stunning: Wonder earned creative autonomy, an advance of nearly $1 million and substantial annual guarantees, while his royalty rate shot up to 14 percent. The new three-year contract took effect on July 1, 1971, as sessions for Music of My Mind continued.

"That's what happens when you build people, [when] you pull out the potential in them," Gordy later mused. "You have to be prepared for their independence."

Along the way, Wonder had gotten serious about his music, and about his message. There was an exuberance that remained, but he wanted more.

"Hopefully, that little boy will always stay in me," Wonder told Billboard. "The part of me that's still eager to discover, who welcomes new, unbroken ground. When that ground is being broken, there's a place that says to me, 'Take the you in there who is aware, but let the youth in you that remains curious lead the way.'"

Listen to Stevie Wonder's 'Superwoman (Where Were You When I Needed You)'

Music of My Mind certainly succeeded by that measure. Released on March 3, 1972, the LP gets off to a leaping start with the funk-rocking "Love Having You Around," before unleashing its best song – the two-part, eight-minute "Superwoman (Where Were You When I Needed You)." (Its second segment serves as a kind of sequel to 1971's achingly gorgeous "Never Dreamed You'd Leave in Summer.") "Girl Blue" gets all post-psychedelic, while "Evil" closes the album on a soaring synthesizer-driven note.

DIY and quirky, Music of My Mind was almost entirely performed by Wonder, save for one-off guitar and trombone turns by sidemen. Cecil and Margouleff helped Wonder with programming the polyphonic Original New Timbral Orchestra synth rig, earning co-producer credits.

Wonder had first heard these exciting new sounds on their 1971 album Zero Time, recorded as Tonto's Expanding Head Band. "The reason that I got into [Tonto] was that I had ideas in my head," Wonder told PBS, "and I wanted those ideas to be heard." The technology was another important step away from Motown's built-in music-making structure, too.

"Stevie was apparently quite taken by the idea that this was a keyboard instrument that he could possibly play that made all of these sounds," Cecil told the BBC. "He was tired of having to play his songs to an arranger who would then go away and write the arrangement, record the track with the band, call Stevie in after it was recorded, tell him where he had to sing, what he had to sing and then send him away again while they did the mix. And Stevie said it sounded nothing like what the song sounded like in his head."

The rhythms still had an untutored playfulness, as he found his way on a new instrument. But Wonder is such a fast learner that he was already one of the best drummers on the planet just one album later. "Superwoman (Where Were You When I Needed You)," with its ARP synth whirl and gurgling Moog bass, completes the unfolding roadmap to Wonder's brilliance.

In the meantime, Music of My Mind set new standards for R&B, new standards for tech and new standards for artistic independence at Motown, while getting to only No. 21 on the Billboard album chart. We now know Stevie Wonder was just getting started.

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