For Jay-Z, hopes of tuning in

AS a rapper, Jay-Z has been one of the most bankable names in pop over the last decade. Thanks to such irresistible hit singles as “99 Problems,” the New Yorker has sold more than 20 million albums.

But as the fine print in stock portfolios always notes, past success is no guarantee of future performance, especially when someone with success in one arena steps into another, as Jay-Z did in January, when he was named president and chief executive of Def Jam Recordings.

“Just because you have a big-name person behind you, it doesn’t mean that it’s going to carry you,” singer Teairra Mari said by phone this week from Washington, D.C., where she was promoting her debut album, “Roc-A-Fella Records Presents Teairra Mari.”

“It just let me know that no matter what, you’ve just got to work hard.”

As it happens, her album, on Jay-Z’s Def Jam-owned Roc-A-Fella imprint, entered the chart last week at No. 5, on first-week sales of 69,000. She and R&B; singer Rihanna are Jay-Z’s latest finds.

The hip-hop label’s first two releases after he took over -- new efforts from rapper Memphis Bleek and rap duo Young Gunz -- have sold about 250,000 copies combined.

More encouraging for Jay-Z (real name: Shawn Carter), “Let’s Get It: Thug Motivation 101,” the debut album by Atlanta rapper Young Jeezy, entered the pop chart at No. 2 on Aug. 3 after selling 172,000 copies in its first week in stores. It dropped to No. 4 this week with sales of 85,000.

Mari took the unusual step in modern-day R&B; and rap of not having guest vocalists on her album. “I wanted people to get a sense of who I am,” she said. “I didn’t want them to like the songs on my album because this person or that person was on it.”

Rihanna, a Barbados-born singer whose music has a Caribbean bent, didn’t go overboard on A-list guests either. “Music of the Sun,” her debut album, scheduled for an Aug. 30 release, features reggae stars Elephant Man and Vybz Kartel, neither of whom is a mainstream draw for American fans.

Nonetheless, a leading retailer sees tremendous potential for Rihanna.

“That type of music is hot,” says Violet Brown, director of urban music for Wherehouse Music. “There is not another female doing it on a major label with major people behind it. This is going to be huge.”

Despite the attention the Jay-Z push may be affording them, neither Mari’s “Make Her Feel Good” nor Rihanna’s “Pon De Replay” is getting much radio support from any of Los Angeles’ major urban stations, but “Pon De Replay” is a Top 10 song at local pop music station KIIS-FM (102.7).

In other parts of the country, however, both songs are showing radio muscle. Mari’s single is big in New York, and Rihanna’s is strong in Philadelphia.

Even though Jay-Z is enjoying a publicity blitz in his new position at Def Jam, this is not his first time running a label. With Damon Dash and Kareem “Biggs” Burke, Jay-Z co-owned and operated Roc-A-Fella Records, which released its first album, Jay-Z’s “Reasonable Doubt,” in 1996.

Besides releasing Jay-Z’s material, the imprint had an uneven track record. Stalwarts were Kanye West and DJ Clue?; other artists included Memphis Bleek and Young Gunz, who aligned themselves with Jay-Z when he broke ties with Dash and Burke less than a year ago. (Jay-Z still owns and runs Roc-A-Fella, while Dash and Burke started the Damon Dash Music Group, which, like Def Jam and Roc-A-Fella, is distributed by Universal.)

Although her music career is just getting started and offers are steadily pouring in for movie roles and endorsements, Mari said Jay-Z has already taught her an important career lesson.

“Just to know that it’s a marathon, not a sprint,” Mari says. “Some people will go crazy if they don’t have success the first time, the first go-round. He just told me to be in it for the long run, the life of it. It’s not about first-week sales, one song. It’s about having a life to your career.”