Robert Jens Rock is a Canadian record producer, sound engineer and musician, best known for producing rock bands and music artists such as Metallica, Mötley Crüe, Bon Jovi, Aerosmith, the Tragically Hip, the Cult, 311, Our Lady Peace, Bryan Adams, the Offspring, Michael Bublé, Black Veil Brides, David Lee Roth, and Ron Sexsmith. Wikipedia