BORN TO BE WILD by PatrickMusicLive

With the line "heavy metal thunder," this became the first popular song to use the phrase "heavy metal," which became a term for hard rock. William Burroughs is credited with coining the phrase, as he used it in his 1961 novel The Soft Machine, describing his character Uranian Willy as "the Heavy Metal Kid." Burroughs told The Paris Review: "I felt that heavy metal was sort of the ultimate expression of addiction, that there's something actually metallic in addiction, that the final stage reached is not so much vegetable as mineral."
This was used in the 1969 movie Easy Rider, a counterculture classic starring Dennis Hopper and Peter Fonda as bikers who ride from Los Angeles to New Orleans. Another Steppenwolf song, "The Pusher," was also used in the film.

When the movie was in production, this was simply a placeholder, since Fonda wanted Crosby, Stills and Nash to do the soundtrack. It became clear that the song belonged in the movie, and it stayed. Partly because of it's use in Easy Rider, this has become the song most associated with motorcycles.