Hip-hop mogul Jay-Z can, and frequently does, claim credit for an array of youngsters who have blossomed thanks to his support: Kanye West, Just Blaze and a number of first-growth French wines. But none of his investments has yielded as large a return quite as quickly as 19-year-old popstress Rihanna.

Shortly after being named president and CEO of Def Jam, the rapper signed the then-16-year-old Barbadian beauty queen and singer Robyn Rihanna Fenty to his roster. (She was first spotted by an American vacationing on the island who, conveniently enough, happened to be music producer and songwriter Evan Rogers.)

Def Jam quickly pushed her first single, the dancehall-influenced “Pon de Replay,” to No. 2 on the singles chart in advance of debut album, “Music of the Sun,” which moved respectable numbers in 2005.

After an enviable slot opening for Gwen Stefani on her U.S. tour, Rihanna released follow-up “A Girl Like Me” in 2006, scoring the singer her first No. 1 single, “S.O.S.” But it was this summer’s “Good Girl Gone Bad,” which saw Rihanna adopting a more provocative, grown-up image, that truly moved her into R&B’s top tier.

Lead-off single “Umbrella” entered the U.S. charts at No. 41, then immediately jumped to No. 1, where it remained for seven straight weeks. In the U.K., the track held top position for 10 weeks, the longest chart reign for a female artist there since Whitney Houston put out the equally ubiquitous “I Will Always Love You” in 1992.

Yet unlike Houston and her other predecessors, Rihanna mostly eschews broad, melismatic gestures for a Caribbean-tinged, often monotone, vocal delivery, and “Good Girl Gone Bad” plays to her strengths. By emphasizing that distinctiveness, as well as boasting a stellar list of contributors (including Justin Timberlake, Timbaland and CEO Jay Hova himself), the album also attained the kind of critical recognition that could be essential in separating Rihanna from her crowded peer group — even the terminal curmudgeons at Pitchfork gave the record a relative rave.

With a second single — the New Order-sampling “Shut Up and Drive” — already in heavy rotation and a modeling contract with Cover Girl, Rihanna could be well on her way to establishing an empire of her own.

Recent breakthrough: Provided summer 2007 with its most inescapable tune; discovered several new syllables within the word “umbrella”; anchored the Tokyo leg of July’s Live Earth concerts.

What’s next: A fall tour through Europe and North America with fellow hot commodity Akon.