A musical mat of the present invention includes a mat portion having a pillow connected to one end thereof. The mat includes a casing with a resilient padding material therein for supporting a person. A pair of speakers are mounted in the pillow and spaced apart so that a person can lie with his head...http://www.google.es/patents/US4841587?utm_source=gb-gplus-sharePatente US4841587 - Mat with sound system
