Here are 16 bands and musicians who are considered pioneers of heavy metal.

Just like there's no definitive answer as to how Earth formed, there is truly no definitive answer as to which band "invented" metal.

The Beatles and the Rolling Stones may have been the biggest rock 'n' roll bands throughout the early to mid-1960s, but it was The Who, The Kinks, Jimi Hendrix and Cream who really began pushing the limits and innovating with their equipment to create the distorted, deep sounds that defined heavy metal in the coming years.

Some will argue it was Led Zeppelin who swallowed their rock and blues predecessors' sounds and thus regurgitated metal, others will say Black Sabbath. Various sources say it was those two plus Deep Purple.

But even the styles of those three bands were a result of the way rock music was evolving throughout the '60s, combining blues, distorted garage rock, acid rock and psychedelia. The birth of heavy metal was a culmination of bands experimenting with heavier sounds, like an intensely flavored musical stew.

READ MORE: Who Really Invented Heavy Metal?

Groups began releasing heavy albums left and right starting around 1970, which was a whole five decades ago as of this year. We compiled a gallery of bands and musicians considered "proto-metal" who are credited for pioneering the genre. Whether it was a single song, instrumental technique or attitude, these artists are the roots of heavy metal.

See metal's pioneers in the gallery below.

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16 Bands + Musicians Who Are Considered Pioneers of Heavy Metal

These rock and metal bands are considered pioneers of heavy metal because their different styles and techniques are still utilized in metal today.

Gallery Credit: Lauryn Schaffner

For more metal history, see the best metal album of each year since 1970 below.

The Best Metal Album of Each Year Since 1970

See Loudwire's picks for the Best Metal Album of Each Year Since 1970.

Gallery Credit: Loudwire Staff

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