Ever since fusion devolved into flaccid pop-jazz in the 1980s, the genre has been treated with suspicion by more than a few jazz snobs. In fact, fusion didn't get a fair shake right out of the gate. When Miles Davis went electric and started performing before rock audiences, critics couldn't stop condemning the man. "SELLOUT!" they proclaimed ad nauseam, even though the music he made was wildly challenging and ambitious.
Between 1969 and 1976, fusion's first and second waves produced some of the most powerful and forward-looking music of the post-hippie rock landscape. This is the era I'll spotlight here. Now, it's important to point out that fusion took on many forms throughout the 1970s. In addition to rock, jazz mingled with funk, Latin music and even avant-garde classical. We'll touch on all these incarnations. That said, the decade also produced something called "jazz-rock," a phrase critics and fans often used when talking about Blood, Sweat & Tears; Chicago; The Electric Flag; and similar ilk. These artists don't figure here; however, definitely check out my Cheat Sheet on Classic East Coast Horn Rock, if you dig classic rock with brass and horns. And while I'm touching on related topics, do explore my Krautrock Cheat Sheet: much like progressive rock, the German movement had quite a lot in common stylistically with fusion.