What makes Ommadawn by Mike Oldfield notable?

'Ommadawn' reached significant commercial success, peaking at number one on the UK Albums Chart and reinforcing Oldfield's innovation in blending genres. The album has been influential within the ambient and progressive rock genres, noted for its intricate structure and rich sonic landscapes that inspired a generation of musicians. Released on October 21, 1975, 'Ommadawn' was Mike Oldfield's third studio album, following the groundbreaking success of his debut, 'Tubular Bells'. At this point in his career, Oldfield was solidifying his reputation as a pioneering artist in the progressive and new age music scenes, exploring deeper musical narratives and diverse instrumentation.