Helter Skelter is a song by the Beatles and is considered by music historians to be a key influence in the early development of heavy metal.
In other words, The Beatles were the first band to experiment with heavy metal. A lot of people, these days, can’t understand why this amazing British band is considered the best ever. The fact is that they actually experimented with and pioneered a lot of musical styles including Heavy Metal. I would say that Rock, Progressive and even Dance would not be possible today without the work of Lennon and McCartney. The Helter Skelter song was a product of McCartney’s attempt to create a sound as loud and dirty as possible and has been noted for its “proto-metal roar”. You can read more details here.