The Mellotron. The Instrument That Created Progressive Rock.
We're looking at the history of the Mellotron.

Progressive rock is a genre of music that may not be for everyone. To some casual music listeners, the "strange" music, long compositions, and fantastic lyrics, can be off-putting, but to many others, these are the exact reasons they love the genre. There are a lot of prog bands with different sounds, but the genre has some universal elements and instruments, one of them being the Mellotron.
A New Invention
The Mellotron was developed in Birmingham, England in 1963, based off an older keyboard model, the Chamberlin. Before it was adopted by musicians, some of its earliest users were actually celebrities, including Princess Margaret, Peter Sellers, King Hussein of Jordan, and founder of Scientology L. Ron Hubbard.
A Prevalent Sound
One of the first musicians to use the instrument was Graham Bond, who used it on his single "Baby Can It Be True". Other early adopters included:
Mike Pinder (The Moody Blues)
John Lennon and Paul McCartney (The Beatles)
Brian Jones (The Rolling Stones)
Ian McDonald and Robert Fripp (King Crimson)
Tony Banks (Genesis)
Jethro Tull
Rick Wakeman (Yes)
Rick Wright (Pink Floyd)

A Legacy of Sound
Since the first Mellotron was invented, there have been 15 different models, and countless users. Each model has sought to build off the previous one, and each continues to push the boundaries of progressive rock music. It's an instrument with a tone that defined an entire genre. Older ones are valuable and highly sought after, and artists still use them in recordings today.