Twenty albums at 20

Twenty years ago, the world rocked a lot harder than it does today. Back then, grunge started its smack down of the mainstream, driven by pivotal CDs like "Nevermind" and "Ten". Gangsta rap spread wider and started to outrage the mainstream, via N.W.A. and Ice T. And heavy metal found a new pride with the continued reign of Guns 'N Roses. At the same time, tame stuff had a significant impact as well. Mainstream stars Mariah Carey, Michael Jackson, Michael Bolton, and Amy Grant saw some of their sales peaks. Here's a look at 20 albums that shook the world - discs which, for better or worse, will forever define their time. Mariah Carey "Emotions" (September 17th, 1991) Mariah Carey's second album didn't have the massive impact of her debut, but it still sold over 3 million copies and expanded the singer's sound, mixing more classic pop into her slick '90s mix. The disc's most enduring single remains the title track, which boasts a '70s feel. The album also produced one of Carey's most danceable tracks, "Make It Happen" (co-written with Robert Clivilles and David Cole of C&C Music Factory fame). Another song saw Carey collaborating with Carole King ("If It's Over"). (excerpt from New York Daily News)