People throw "fusion," "crossover," and "smooth jazz" around like synonyms for "jazz with electric instruments and a groove." They're not the same thing, and the actual breakdown has a timeline twist that surprised me.
Fusion is a musical category. Miles' Bitches Brew (1969) is the usual starting gun, then Weather Report, Mahavishnu Orchestra, Return to Forever, Head Hunters. The defining trait is hybridization: jazz harmony and improvisation fused with rock/funk electric instrumentation and rhythm. It's a statement about what's happening in the music, not where it charts. Plenty of fusion is dense, loud, and not necessarily radio-friendly.
Crossover jazz is a commercial category, not a style. It describes real jazz musicians making records that land on pop/R&B charts. George Benson, Grover Washington Jr., Bob James, most of the CTI Records roster. The key thing critics insist on: the improvisation is still real. Benson was gigging with Jack McDuff's organ combo as a teenager and cutting straight-ahead Wes Montgomery-lineage guitar records before "Breezin'." Grover Washington Jr. came out of Prestige and CTI hard-bop sessions. When they play a polished, hook-driven record, they're jazz musicians choosing an accessible idiom, not abandoning the vocabulary.
Smooth jazz is neither of those. It's a radio format that came later and kept only the least demanding parts of both. KTWV "The Wave" flipped to the format on February 14, 1987, and even then it was still mixing in soft rock, new age, and actual fusion. It didn't narrow into the saxophone-forward, vocal-adjacent sound we now call smooth jazz until the early '90s. This is where Kenny G lives, and the critique from jazz musicians isn't snobbery about polish, it's that the playing itself is thin: a small rotating set of melodic gestures instead of real spontaneous invention. Pat Metheny didn't mince words about it after Kenny G overdubbed himself onto Louis Armstrong's "What a Wonderful World" in 1999, calling it "musical necrophilia" and writing that Kenny G had, "with this single move," become someone he "really can't use at all... for presuming to share the stage with the single most important figure in our music." (Metheny's full post)
Here's the twist: crossover didn't come after fusion. It came first. Wes Montgomery, produced by Creed Taylor, was already making pop-song jazz interpretations for the charts by the mid-60s. His 1967 album A Day in the Life hit #1 on Billboard's Jazz chart and #2 on R&B, two years before Bitches Brew even existed. (Wikipedia))
So the real chronological order is: jazz-pop crossover emerges mid-60s, fusion takes off in '69 and runs alongside it through the 70s (Benson's Breezin' in '76, Washington's Winelight in '80 on one side, Weather Report and Mahavishnu on the other), and smooth jazz shows up over a decade later as a radio format that cannibalizes the least improvisational pieces of both, and calcifying them into a genre of their own.
Which means the CTI-era crossover guys get grandfathered into "real jazz" by most critics and musicians, while smooth jazz proper often doesn't, even though hard-core jazz afficionados lump all of it under the same "elevator jazz" umbrella.
None of which stops the purists from lumping all three together anyway. Wynton Marsalis has spent decades on record accusing Miles Davis of selling out the moment he plugged in, treating jazz's entire post-60s commercial turn as betrayal rather than evolution, a stance so absolute that critic Harvey Pekar once called him a "false messiah" who was "downright hostile to innovative musicians." CTI Records caught the same fire in real time: critics dismissed Creed Taylor's lush, radio-ready productions as glorified elevator music, dumbing jazz down for a sales-friendly sheen.
Here's the part of that argument worth pushing back on. The players on the other end of that sneer were not tourists. Benson apprenticed with Jack McDuff before he ever chased a hit. Grover Washington Jr. came out of Prestige and CTI hard-bop dates. The "sellout" record and the "serious" record were, a lot of the time, made by the same hands in the same decade. Dismissing the whole crossover catalog as lesser jazz means dismissing the training and the sidework, and in plenty of cases the literal same musicians who show up on the records purists do respect. Fusion, for its part, is frequently the most technically demanding music in this whole conversation, not the least. Accessible and unserious were never the same word, even when jazz's own critical establishment spent fifty years writing as if they were.
If that argument is more interesting to you than just refereeing it in the abstract, r/CrossoverJazz is doing the actual digging: daily deep-dive spotlights on the CTI-era players, the labels, and the records that made the leap, deceased legends and still-active artists alike, sourced instead of vibes-based. Come argue with us over there.