Home Features Metallica Producer: A Cool Trick I Used On ‘Sanitaritum’ Intro, You’ll Need Headphones To Hear It [News] Metallica Producer: A Cool Trick I Used On ‘Sanitaritum’ Intro, You’ll Need Headphones To Hear It [News] planetsixstring August 17, 2017 comments off Tweet on Twitter Share on Facebook Google+ Pinterest Music News: Flemming Rasmussen also remembers the first time Metallica used click track.