For the last in Eno's initial series of Ambient recordings, he eschews, for the most part, the use of conventional instruments and melodic concepts. Instead he utilizes found sounds—indigenous music, mechanical sounds, the sound of chains and stones and more, to create an album of time and place. Ambient 4: On Land is even more about experience and less about conventional listening; music that is meant more to be felt than heard. Music that, through its combinations of found sounds processed and placed in well-considered places in the stereo image—this is a recording that is best listened to in headphones—evokes strong imagery of places real and imagined.
Eno even references earlier works, extracting bits and pieces and subsuming them into a new whole. Eno compares this process to composting, "converting what would otherwise have been waste into nourishment." While one might argue Eno's calling any of the source material for this recording waste, he clearly has a vision—although to call it merely a musical vision might undervalue it—that involves drawing sound from a variety of sources, from the inherently musical to the less traditional, and shaping it into deeply provocative textures. Eno may never have been to "Lantern Marsh," located near where he grew up in East Anglia, but he has a vivid impression of what it must be like and, consequently, fashions a piece that, like the rest of the works on On Land , is intensely visual.
Eno would continue to investigate the potential of sound as a part of the atmosphere, including the ability to investigate more extended pieces made possible by the time-liberating capabilities of the compact disc; but on these four early experiments in Ambient Music he has fashioned four distinctly different aspects of the same concept. From the trance-like nature of Discreet Music to the more soothing background of Music for Airports ; from the lyrical beauty of The Plateaux of Mirror to the more uniquely visual aspects of On Land , Eno truly broke new ground with each recording, creating a style of music that would inspire countless other artists, although none would ever achieve such innocent purity and vivid imagery.-http://www.allaboutjazz.com/php/article.php?id=15608