Some artists establish alternate personas to express themselves in an all-new fashion. A few became fun deviations from the norm, while others left fans scratching their heads.

The Oracle breaks down some of the most significant musical alter egos, from those who added a new dimension to their art form to those who will go down in history as eccentric failures.

Eminem/Slim Shady

The best selling hip-hop artist of all time received a little help from his pill-popping, misogynist persona known as Slim Shady. Through the screechy-goofball alter ego, Eminem didn’t just get away with saying whatever he wanted, he got paid millions to do so. The Slim Shady LP went triple platinum in 1999 and catapulted the Detroit rapper to superstardom.

Why it worked: It was funny. Whether he was rapping about stapling his teacher’s genitalia to a stack of paper or attacking Moby with homophobic slurs, Slim Shady had kids laughing and parents fuming.

The degree to which parents loath something is often inversely proportionate to how much kids love it. Eminem was clever and cool enough to make Slim Shady a pop culture phenomenon and not just another Insane Clown Posse, banking off of pure shock value.

Garth Brooks/Chris Gaines

Maybe Garth Brooks was tired of being the most successful artist of his genre when he decided to get a black emo haircut and grow a soul patch to embrace his inner rock and roll.

For whatever reason, in 1999 Brooks revealed his alternative rock ego, Chris Gaines, with talks of a movie focused on the character and an album to promote it. Unfortunately for Brooks and Gaines, the movie never got off the ground and the album did little more than confuse the legions of his diehard country fans.

Why it sort of worked: The album did make it to No. 2 on the American charts. Though it wasn’t considered a great success, it made for some memorable moments. VH1 made a mockumentary “Behind the Music” episode revolving around the persona. Garth Brooks also hosted Saturday Night Live with Chris Gaines appearing as the musical guest.

Joaquin Phoenix the actor/Joaquin Phoenix the rapper

After losing the Oscar for Best Actor in 2006 for “Walk the Line,” Phoenix made a surprise move by announcing his retirement as an actor to pursue a career in the rap game in October 2008. It surfaced later, after he made a confusing appearance on the Tonight Show with David Letterman and filmed a documentary with Casey Affleck, that his new, scruffy-bearded persona was all an elaborate hoax.

Why it failed: No one got it, and no one cared. The mockumentary, “I’m Still Here,” detailed Phoenix’s attempt to make it as a rapper. Maybe, had he been a bit more upfront with the non-serious nature of this stunt, people would have embraced the social commentary. But because no one knew until after the film was released, it went down as nothing more than a bad joke.

Teen alter egos

Miley Cyrus got famous through her alter ego. Keeping her identity secret was the basis of her Disney Channel TV show, “Hannah Montana.” Justin Bieber, on the other hand, found fame being himself, but thought he could use a break. Thus, his rapping alter ego, Shawty Mane, was born. Though this was probably nothing more than a fun YouTube stunt, Bieber should probably stick to being cute and cuddly.

Throwback alter egos

Easily two of the more successful musical alter egos are David Bowie’s Ziggy Stardust and The Beatles’ Sgt. Pepper’s Lonely Hearts Club Band. Both were used to explore different sounds. Sgt. Pepper’s Lonely Hearts Club Band was a fun, alt-Beatles album that derived from band members branching out during a brief musical hiatus in the mid-’60s.

Ziggy Stardust was a pop-star hyperbole that created the Bowie Cult in the ’70s. Both are heralded as great commercial successes, paving the way for similar stunts in the decades to come.

Diva alter egos

Beyonce’s Sasha Fierce and Lady Gaga’s Jo Calderone represent the latest attempts at persona expansion. Sasha Fierce was the title of Beyonce’s 2009 album and embodied the bold new attitude of her music. Calderone was the latest in the “what-will-she-do-next” Gaga stunts, as she hosted the 2011 MTV Video Music Awards dressed as a Billy Joel-esque Italian man who perpetuated male stereotypes.