TV’s pop music coaches

Leona Lewis took the crown on Simon Cowell‘s original “The X Factor.” A three-time Grammy nominee, Lewis is the only winner from the series to find massive success in the U.S. Her debut album, 2007’s “Spirit,” was the first time a British solo artist bowed on the Billboard 200 chart at No. 1, and her single “Bleeding Love” set a radio airplay record.

How you know her: Her 2007 single “Bleeding Love” was inescapable on Top 40. The track went No. 1 in more than a dozen countries, including the U.S., and sold more than 9 million copies. It was nominated for record of the year and female pop vocal performance at the 51st Grammy Awards.   (Mike Coppola / Getty Images)

Sara Bareilles came to NBC’s “The Sing-Off” with an advantage: the Grammy-nominated songbird got her start in an a cappella group as a student at UCLA. Her major label debut, 2007’s “Little Voice,” was led by the set’s smash, “Love Song.” Bareilles’ sophomore set, “Kaleidoscope Heart,” debuted at No. 1 on the Billboard 200, selling 90,000 copies in its first week.

How you know her: “Love Song,” her defiant ode about not chasing a hit, became a major one when it landed at the top of Billboard’s Pop 100 chart and earned her two Grammy nominations.  (Kirk McKoy / Los Angeles Times)

Nicole Scherzinger has the rare distinction of being the lead singer of two girl groups. She broke into music after being picked to front Eden’s Crush through the WB’s “Popstars.” However, she achieved most of her fame with the Pussycat Dolls. Though the group had plenty of hits, the focus on Scherzinger led to plenty of group turmoil, and she departed to focus on her solo career.

How you know her: As a Doll she’s logged plenty of hits, including “Don’t Cha,” “Buttons” and “When I Grow Up.” Her solo career hasn’t been as smooth in the States, and her serially delayed debut arrived to moderate success overseas in March. It will hit U.S. stores in November.  (Christopher Polk / Getty Images)

Chances are Antonio “L.A.” Reid, the only non-singer on this list, is responsible for signing your favorite performer. Before leaving his post at Island Def Jam to discover talent on the U.S. edition of “The X Factor,” Reid worked as president and chief executive of Arista Records and was co-founder and co-president of LaFace Records. He’s had a hand in albums from artists including Mariah Carey, Justin Bieber, Kanye West, the Killers, Bon Jovi, Jennifer Lopez, Rihanna, Avril Lavigne, Pink, Usher and OutKast. The Grammy Award-winning producer was recently named chairman and chief executive of Epic.

How you know him: Pink’s 2002 hit “Don’t Let Me Get Me” takes a jab at Reid’s assertion that she needed to stick close to the R&B/pop of her debut album.   (Chris Pizzello / Associated Press)

Jennifer Lopez’s co-headlining show with Enrique Iglesias scheduled for Sunday at the Honda Center in Anaheim has been canceled.   (Christopher Polk / Getty Images)

As one-fourth of the Black Eyed Peas, will.i.am, left, and his crew have held a stronghold on pop music for the better part of the decade. Though the Peas continue to be unrivaled players on the chart, will.i.am has branched out to produce hits for other artists including Britney Spears, U2, Estelle, Rihanna, Usher, Justin Timberlake and Nicki Minaj.

How you know him: We have faith you can hum a line from a recent BEP track, but will.i.am is also the man behind Usher’s dance hit “OMG,” Estelle’s breakout “American Boy” and, of course, your favorite BEP hit.   (Ethan Miller / Getty Images)