By Emily Feimster From the earliest days of theater, through vaudeville and in such recent show business giants as Sammy Davis, Jr., it was the rule for performers to be able to sing, or dance, or tell jokes, or play an instrument - or all of the above - in addition to acting. Then came a shift, perhaps we should blame the age of specialization, and for awhile it became news when a thespian crossed the line to try recording, or a pop music star ventured into acting. Today, however, we're seeing the rise of the multi-talent all over again - in exciting new ways. It's not only household names like J Lo and Madonna, who've been exploring all sides of the entertainment industry for much of their careers. It's a group of super-talented names who are not only covering lots of show business bases, they're making it look easy.

When it comes to being multi-faceted, Jamie Foxx certainly knows no boundaries. He studied classical piano at Juilliard before making it big as a comedian on the show "In Living Color." Fast forward 14 years and he's already won the Best Actor Oscar for his work in "Ray" and this year he was nominated for a Grammy for the song "Creepin" off his humongous hit album "Unpredictable." Then, of course, there was his show-stopping Grammy Awards performance with Kanye West, with both leading hip-hop marching bands. Is there anything he can't do?

Another comedian entering the music world is Nick Cannon, who recently told us, "Right now I'm focusing strictly on my music because I've got my own record label that I started, [Can I Ball Inc.], off of Motown Records." Not only will Cannon be releasing a rap album in the Spring, but he's also trying his hand at drama with the movie, "Bobby," co-starring Lindsay Lohan, who's also no stranger to double dipping. After signing a record contract with Casablanca Records, Lohan debuted her 2004 album, "Speak," which went platinum. In late 2005, her second album, "A Little More Personal (Raw)," was released, although most of her focus still remains on acting.

Lohan's former rival, Hilary Duff, can't seem to pick just one passion either. The one-time "Lizzie McGuire" star decided she wanted to be on stage after seeing her sister, Haylie, perform in a band. Duff then made the album, "Metamorphosis," which debuted at number two on the Billboard 200. She's since released three more albums, with the most recent, "Most Wanted," being co-produced by her rocker boyfriend Joel Madden.

Speaking of being inspired by one's sister, Ashlee Simpson began her career as a backup dancer for Jessica before becoming an actor on the WB drama "7th Heaven." After some encouragement by her friend and guitar player, Ray Brady, Ashlee began to sing as well. Her debut album "Autobiography" went triple platinum, although she's had a few rough patches along the way - think "Saturday Night Live" and the Orange Bowl. Her follow-up album, "I Am Me," debuted at number one, but sales quickly deteriorated.

Most people don't even think of the Oscar-nominated Will Smith and Queen Latifah as rappers since their acting careers took off. Mos Def, though still respected in the music industry, has been a major player on Broadway and was nominated for an Emmy for the HBO movie "Something the Lord Made." Even rapper Ludacris is getting major props for his roles in the critically-acclaimed movies "Hustle & Flow" and "Crash."

Not only is Beyonce Knowles hot on the dance floor, but she's also been sizzling on screen with the movies "Austin Powers in Goldmember" and "The Pink Panther." Her next project is "Dreamgirls" alongside Jamie Foxx and Eddie Murphy.

Mandy Moore, who's already released four albums, has also used her girl-next-door charm to transition herself into a fine actress. We'll see if 15-year-old pop singer JoJo, can do the same with her upcoming movie "Aquamarine" co-starring Emma Roberts. Of course, Alicia Keys has a lot to prove as well with her movie "Smokin' Aces."

Let's not forget Tim McGraw, who first turned heads in "Friday Night Lights," and now has the movie "Flicka" premiering in July, and rapper Bow Wow, who has "The Fast and the Furious: Tokyo Drift" and "Mr. Prez" on the way. Other musicians who've made a bang as actors include Jon Bon Jovi, who has a string of credits including a recurring role on "Ally McBeal" and recently appeared in episodes of "Las Vegas" and "The West Wing." And Harry Connick Jr., who went from "Hope Floats" to "Will & Grace." And Reba McEntire, who has her own WB sitcom, "Reba." And L.L. Cool J, whose most recent movie was "Last Holiday" with Latifah.

Next up, we have Justin Timberlake hoping to make a name for himself as an actor. He's been taking a break from music in order to make the movies "Edison" with Morgan Freeman and the independent flick "Alpha Dogs." He must not be too bad considering he's already got three more projects in the works - "Black Snake Moan" with Samuel L. Jackson, "Southland Tales," and "Shrek 3."

So with all of these entertainers hopping back and forth over career lines, who knows what's next? Before you know it, we'll have actors, musicians, and even athletes performing things like ballroom dancing or ice...skating...Oh, wait.