Robert's audition and hiring appear in the documentary film Some Kind of Monster.
Robert replaced Jason Newsted as Metallica's bassist on February 24, 2003.
He has a son named Tai Orion.
Robert uses a five-string bass.
The St.Anger album was his first album with Metallica.
Robert uses his fingers and at times a pick when playing the bass.
He has played in Metallica, Suicidal Tendencies, Black Label Society, Infectious Grooves, and with Ozzy Osbourne.
Robert: Playing for Metallica is like having free speech in Cuba.