Instruct: Classify Amazon reviews into positive or negative sentiment
Query: An amazing sonic experience -- under the circumstances

I loved this album back in 1972 and I'm still amazed by it's sonic impact today. Deep Purple's recording engineer Martin Burch was asked to capture some shows from the 1972 Machine Head Tour on tape. During the August 1972 Japanese leg of the tour, he had his chance to record. Burch was supplied with an unimpressive, cheap looking Ampex 8-track recorder to get the job done. Burch was dissapointed with the equipment he was given and was certain that the results would be a total waste of his time.When the entourage arrived back in England, Burch took the time to throw the eight track recording tapes onto a studio deck and have a listen. COMPLETE AND TOTAL SHOCK !!! The combination of skillful microphone placement, concert hall acoustics and the unexpected superior performance of that little Ampex tape deck had collectively ganged up to capture one of the finest quality live rock recordings of all time.