At first glance, it seems like Robert Trujillo has been with Metallica since day one. He's comfortable with the band during interviews and press conferences, his bass style fits perfectly with the rest of the crew and he absolutely owns the stage when he wants to during live shows. However, he's the newest member of the band, though, jumping on board officially on February 24, 2003. Nearly a decade later, Trujillo has definitely earned his spot with the legendary band.

Born on Oct. 23, 1964 in Santa Monica, Calif., Trujillo is a master of rhythm. Trujillo a mad scientist when it comes to jamming on the bass guitar, primarily focusing on plucking the strings with his fingers. It's because of this talent that Trujillo was able to climb his way up the metal ladder to the top and replace Jason Newsted in the new millennium.

From the late 1980s to the mid-90s, Trujillo played with the influential thrash outfit Suicidal Tendencies, playing on several studio albums including arguably one of the band's greatest records, 'Lights ... Camera ... Revolution!' As the band began to disband in the mid-90s, Trujillo began focusing on a side project he formed with Suicidal's fearless leader Mike Muir known as Infectious Grooves. He played bass on all four of the band's studio albums. For those fans lucky enough to see Suicidal Tendencies destroy the Damage Inc. stage at Metallica's Orion Music + More festival, they got to see Trujillo jump onstage and join Muir and company for part of their live performance. His relationship with Muir is doing quite well as evidenced by that memorable experience.

Matt Ellis, Orion Music + More

After his time with Suicidal Tendencies and Infectious Grooves, Trujillo found himself playing with another group of his, Mass Mental?, and Glenn Tipton for a period of time. In the late 90s, Trujillo found himself as a member of the Prince of Darkness' band. That's right, the bassist was playing with Ozzy Osbourne. Trujillo toured with the band and recorded 'Down to Earth' with the heavy metal legend. On top of that, Trujillo re-recorded the bass tracks for the reissues of 'Blizzard of Ozz' and 'Diary of a Madman.' During this time, he became friends with Zakk Wylde and played with Black Label Society for a few live shows and even recorded bass on a couple of tracks of the band's album '1919 Eternal.' After that, Trujillo found himself playing with Jerry Cantrell while he embarked on his solo career.

There's no doubt that Trujillo had built up quite the resume as he auditioned for Newsted's spot in Metallica. He earned every opportunity he had and it paid off as he was hired to join the band that he once supported as an opening act with Suicidal Tendencies. Footage from his audition and the reaction of the band are included in the documentary 'Some Kind of Monster.' In the film, guitarist Kirk Hammett pays Trujillo the ultimate compliment by comparing him to the late bassist Cliff Burton. Newsted used a pick to play the bass; Burton used his fingers. Trujillo's intense finger-playing style obviously stood out to Hammett and the rest of the band.

Now an official part of Metallica, Trujillo's first debut to the public came in the form of the official EP for 'Some Kind of Monster.' While he wasn't a part of the two studio tracks, he was the bassist and backing vocalist on the six live tracks. His first studio album with Metallica was 2008's 'Death Magnetic,' the first album since the release of 'St. Anger.' Every album released since then, whether it was a live disc or the collaboration with Lou Reed on 'Lulu,' Trujillo has been with Metallica every step of the way.

MJ Kim, Getty Images

Primarily jamming on custom Warwick five string basses, Trujillo finds himself picking up an ESP, Yamaha or Zon bass - among others - every now and again. If you're looking to get the same rig as the Metallica bassman, make sure you're blasting through Ampeg or Mesa Bookie cabinets, and arm your weapon with Trujillo's signature Dunlop Icon Series bass strings.

When he's not jamming on his bass and doing sick helicopter spins onstage, you can most likely find Trujillo catching some waves as he is an avid surfer. If not out on the water, he might be on the concrete ocean doing something else he loves: skating. In fact, at 2012's Orion Music + More festival, Trujillo spent a lot of time with fans at the Motorbreath Mini Ramp. The bassist is a serious athlete when it comes to these hobbies, and it was evident at Orion Music + More.

Trujillo has been known to step in front of a camera, too, although it's been a few years since he's made his acting debut. Make sure to check out 1978's 'House Calls' to see the bassist, as well as 1992's comedy 'Encino Man.' You might've seen him in some guest appearances on television, too, including the one and only program 'CHiPs.'

Outside of the band he's called family for the last decade, Trujillo is married to Chloe, with whom he has a son and daughter, Ty and Lula, respectively.

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