A great pop song might feel like magic, but it's actually melodic math (and the helping hand of prolific producer Max Martin) ...

The 90s and 2000s gave birth to some of the best and worst pop songs; here are four that are the best of the worst.

But are her ‘80s-inspired power pop songs and introspective, sweeping ballads appropriate for your children? The music is catchy and fun, though some of its lyrical content may give parents pause.