This is a non-commercial audio check CD distributed and exhibited at the Sony Techno Fair in 1991. It includes various music genres, as well as signals for testing audio performance. Overview: A special edition produced for the "Sony Techno Fair," a technology fair held by Sony. Features: High-quality sound check, gold disc, not for sale. Contents: Genre-less music, audio performance verification signals. Thank you for viewing. Please check the photos for some stains on the case. Please understand that this is a used item.