EMI/Virgin/Polygram's relentless, cut-to-the-chase series of chart-topper compilations can be a grim prospect if it's been a grim year in music, and there have been some doozies. This pleasant retrospective of 1998, however, paints a cheerful, sexy, and reasonably diverse year in mass-music mania. Now That's What I Call Music (whoever "I" is!) features the Disneyland safetypop of the Backstreet Boys' harmonies in "As Long as You Love Me" and Hanson's elevator epidemic "MMM-Bop," as well as the truly 900-number hit "Sex and Candy" by the upstart Marcy Playground. Soulful, dimple-faced girl band All Saints out-Spice Girl the Spice Girls with "Never Ever," and the comparison is immediate with the Girls' own "Say You'll Be There." Cherry Poppin' Daddies' "Zoot Suit Riot" is almost too mature to be included in this gathering, but kids eat this stuff right up. Other nods to the upper-echelon (but not necessarily better-echelon) musical ranks include Lenny Kravitz and his anthemic "Fly Away" and career-destined Radiohead's "Karma Police." Light on angst, a likable and accurate anthology -- even a little R-rated.