Jennifer Lopez is an idealist and an actress--one of Puerto Rican descent--who is convinced she can transcend the stereotypes mainstream Hollywood tends to attach to her heritage. Interestingly enough, Jennifer Lopez also is a realist and an actress who, through her idealism and hard work, actually has managed to transcend those very stereotypes to personify such diverse characters as an Apache Indian, a Cuban jewel thief and a Tejano singing sensation.Her credits range from being a "fly girl" on In Living Color to a transit cop in Money Train . "You have to be able to change your voice," says Lopez, who steps into the pop music limelight this month with her starring role in Warner Bros' Selena. The musical biopic covers the short, but dynamic, life and career of the top-selling Tejano singer who was gunned down by an unstable member of her own entourage. "Selena was a Texas girl and a Mexican, but she had a strong Texas twang and didn't have a Spanish accent like some people think." And though Selena's own voice is used in the movie's concert sequences--a condition on which the artist's father sold the rights to the film--Lopez was eager to speak in a cadence that would meld with Selena's singing tone. "I didn't have to sing in the movie, but I learned how to sing her songs her way, Selena's way. I lip synced to her songs but it appears I'm singing because I am singing. You just can't hear my voice." But, despite the fact that Lopez is virtually a lock for the part--even when it comes to the physical resemblance--the role didn't come easily, Lopez reflects. She had to endure a grueling audition even though she had worked with Selena director Gregory Nava on the film My Family. "Gregory knows me and knows I can act," the actress says with unabashed confidence. "Maybe if Selena had died 50 years ago. But being that she was so fresh in her public's mind, I knew that the movie had to be true to her, and that it wasn't about me trying to become a star in the role. It was important for me to really get the essence of why she was so wonderful, why she was so important in our community, and why she touched the hundreds of thousands of people who mourned her death." Lopez hopes to touch her own audience with her forthcoming performance alongside Ice Cube in April'sAnaconda. Next up is Oliver Stone's film noir thriller Stray Dogs, and she recently appeared in Bob Rafelson's Blood & Wine opposite Jack Nicholson.