On the recorded version of Metallica's Master of Puppets, at the end while the band play the verse riff to close out, it sounds like a second bass with heavy effects playing drawn out notes which add a real haunting effect. Can someone help confirm this is indeed a bass, and perhaps what notes are being played. My guess is octaves of the verse riff. I'm not sure that dropping out of the outro to play those notes would serve the song well, but I'm still interested in giving it a crack. Thanks.