Kidz Bop albums come out so frequently, you could set your watch to their release schedule. Greatest Hits, however, shows that a lot of time has actually flown by since the first collection appeared in late 2001, gathering a baker's dozen of the biggest pop and rock hits as reinterpreted by the Kidz Bop Kids and some grown-up session vocalists. From Smash Mouth's "All-Star" -- which has to be one of the most omnipresent songs of the '90s and 2000s -- to Plain White T's' "Hey There Delilah," Greatest Hits actually does a pretty good job of picking the most popular and most truly kid-friendly songs that have appeared on the Kidz Bop albums over the years. Fergie's materialistic "Glamorous" is a notable exception, but most of the other tracks work well enough in their Kidz Bop versions to not be glaringly inappropriate. A handful of the tracks -- "Hey Ya!," "Since U Been Gone," and "The Sweet Escape" -- are great singles in their original versions and still manage to be fairly listenable for older audiences, but as with all things Kidz Bop CDs, Greatest Hits is for the kids, by the Kidz. ~ Heather Phares, All Music Guide