Ricky Nelson: Ozzie and Harriet's younger son was the rock era's first TV-bred idol. Key song: "Lonesome Town" The Monkees: Concocted as a(n even more) teeny-bopper version of the Beatles, this quartet had its own zany charm. Key song: "Daydream Believer." David Cassidy: The 1970s heartthrob rode the bus with his fake family, the Partridges, and set the stage for his brother Shaun's success a few years later. Key song: "I Think I Love You" The Jackson 5: Motown's family act had great moves, soulful songs and one troubled genius at the center: Michael. Key song: "ABC" Donny Osmond: This puppy lover had the whitest teeth in showbiz. Key song: "Go Away Little Girl" Andy Gibb: Younger brother to the Bee Gees, Gibb made disco perfect for high schoolers. Key song: "I Just Want to Be Your Everything" Rick Springfield: "General Hospital's" Dr. Noah Drake had one big hit but still has a thriving cult career. Key song: "Jessie's Girl" Wham!: England reasserted its reign over teen pop via the duo of George Michael and Andrew Ridgeley. Key song: "Wake Me Up Before You Go Go" New Edition: This Boston-based group's dance moves and harmonies are the root of all things boy-band. Key song: "Mr. Telephone Man" New Kids on the Block: Put together by Maurice Starr, the producer who had discovered New Edition, NKOTB wasn't just that group's vanilla cousin — just ask the fans flocking to see them on this year's reunion tour. Key song: "Step by Step" Debbie Gibson: Along with Tiffany, Gibson embodied the pop version of the John Hughes-movie-style mall rat. Key song: "Only in My Dreams" Kris Kross: This fashion-forward duo showed that rap could be a kiddie affair. Key song: "Jump" Brandy: The prototypical fly ingenue revived girl-group wistfulness for a savvier generation. Key songs: "The Boy Is Mine" (with Monica), "Sittin' Up in My Room" Take That: Huge in Europe, hardly known here, Take That blessed the world with Brit-brat Robbie Williams. Key song: "Pray, Relight My Fire, Babe" Spice Girls: This quintet transformed the energy of punk-rock feminism into an irresistible cheerleader routine. Key song: "Wannabe" Hanson: The Jonas Brothers acknowledge their debt to this bro-trio, which stood out for playing instruments. Key song: "MMMBop" 'NSync/Backstreet Boys: Assembled almost simultaneously by creepy mogul Lou Pearlman, these groups brought the boy-band concept to its logical end. Key song ('NSync): "It's Gonna Be Me"; Key song (Backstreet Boys): "I Want It That Way" Britney Spears: The ruling Lolita of the new millennium had a kitten voice and no qualms about exhibiting her pubescent charms; then she tried to grow up. Key song: "Toxic" Avril Lavigne: This Canadian's snotty-cute music teaches Disney Girls how to toughen up. Key song: "Complicated" Raven-Symone/The Cheetah Girls: The Disney networks' first star of the millennium was not a squeaky-clean rocker but a "Cosby Show" vet. Key song: "Fuego"

Ricky Nelson: Ozzie and Harriet's younger son was the rock era's first TV-bred idol. Key song: "Lonesome Town" The Monkees: Concocted as a(n even more) teeny-bopper version of the Beatles, this quartet had its own zany charm. Key song: "Daydream Believer." David Cassidy: The 1970s heartthrob rode the bus with his fake family, the Partridges, and set the stage for his brother Shaun's success a few years later. Key song: "I Think I Love You" The Jackson 5: Motown's family act had great moves, soulful songs and one troubled genius at the center: Michael. Key song: "ABC" Donny Osmond: This puppy lover had the whitest teeth in showbiz. Key song: "Go Away Little Girl" Andy Gibb: Younger brother to the Bee Gees, Gibb made disco perfect for high schoolers. Key song: "I Just Want to Be Your Everything" Rick Springfield: "General Hospital's" Dr. Noah Drake had one big hit but still has a thriving cult career. Key song: "Jessie's Girl" Wham!: England reasserted its reign over teen pop via the duo of George Michael and Andrew Ridgeley. Key song: "Wake Me Up Before You Go Go" New Edition: This Boston-based group's dance moves and harmonies are the root of all things boy-band. Key song: "Mr. Telephone Man" New Kids on the Block: Put together by Maurice Starr, the producer who had discovered New Edition, NKOTB wasn't just that group's vanilla cousin — just ask the fans flocking to see them on this year's reunion tour. Key song: "Step by Step" Debbie Gibson: Along with Tiffany, Gibson embodied the pop version of the John Hughes-movie-style mall rat. Key song: "Only in My Dreams" Kris Kross: This fashion-forward duo showed that rap could be a kiddie affair. Key song: "Jump" Brandy: The prototypical fly ingenue revived girl-group wistfulness for a savvier generation. Key songs: "The Boy Is Mine" (with Monica), "Sittin' Up in My Room" Take That: Huge in Europe, hardly known here, Take That blessed the world with Brit-brat Robbie Williams. Key song: "Pray, Relight My Fire, Babe" Spice Girls: This quintet transformed the energy of punk-rock feminism into an irresistible cheerleader routine. Key song: "Wannabe" Hanson: The Jonas Brothers acknowledge their debt to this bro-trio, which stood out for playing instruments. Key song: "MMMBop" 'NSync/Backstreet Boys: Assembled almost simultaneously by creepy mogul Lou Pearlman, these groups brought the boy-band concept to its logical end. Key song ('NSync): "It's Gonna Be Me"; Key song (Backstreet Boys): "I Want It That Way" Britney Spears: The ruling Lolita of the new millennium had a kitten voice and no qualms about exhibiting her pubescent charms; then she tried to grow up. Key song: "Toxic" Avril Lavigne: This Canadian's snotty-cute music teaches Disney Girls how to toughen up. Key song: "Complicated" Raven-Symone/The Cheetah Girls: The Disney networks' first star of the millennium was not a squeaky-clean rocker but a "Cosby Show" vet. Key song: "Fuego"