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. He jumped on board officially on Feb. 24, 2003, and, nearly two decades later, there's no question Trujillo has earned his spot with the legendary band.

Born on Oct. 23, 1964, in Santa Monica, Calif., Trujillo is a master of rhythm. Trujillo is 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 started to focus 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 in 2012, 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.

Robert Trujillo - 2012
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.

Watch Robert Trujillo Perform "Believer" Live With Ozzy Osbourne in 2002

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 a 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 or Self-Destruct, Trujillo has been with Metallica every step of the way.

Robert Trujillo Metallica
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.

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.

He also produced the documentary, Jaco, in 2012 about Jaco Pastorius, a jazz bassist whom Trujillo has long respected. Fans may remember the documentary being a significant part of the 2014 edition of Record Store Day.

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.

Watch Metallica Perform "Orion" Live in Costa Rica

Some of Our Favorite Live Photos of Robert Trujillo

If you've ever seen Metallica live in the last 20 years, you know how much of a monster Robert Trujillo is onstage. From his signature helicopter spin to his barking vocals, Trujillo is a musician few can imitate. We could share thousands of photos of Trujillo doing what he does best, but we decided to trim it down to just a few of our favorites.

Sometimes in rock bands, you'll find the bassist is more subdued or prefers to stay away from the spotlight. With Trujillo, he commands the attention of the crowd—and often, the attention of his bandmates—and Metallica's live shows are better because of it.

Check out some of our favorite live shots of Trujillo below, going all the way back to when he first joined the band in 2003.

10 Things We Learned About Metallica from 'Some Kind of Monster'

Metallica: Some Kind of Monster made its debut Jan. 24, 2004, at the Sundance Film Festival. Today, it holds an impressive 89 percent rating with critics 83 percent rating with fans on Rotten Tomatoes. The documentary puts Metallica in a never-before-seen light as the band members opened themselves up in incredibly vulnerable ways. With each viewing, there are still new things fans—hardcore and new fans alike—can learn about one of the biggest bands in the history of rock 'n' roll.

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