When 'N Sync usurped the Backstreet Boys' record of number of albums sold in a single week early in 2000, it had to hurt the Backstreets, since it was played in the press as if they had lost the teen pop throne. By the time the group released their third album, Black & Blue, Thanksgiving week 2000, 'N Sync was still popular, but the arc of No Strings AttachedXillustrated that they were weak where the Backstreets were strong — namely, they couldn't really deliver the seductive mid-tempo pop tunes and ballads that were the backbone of the Boys' crossover success. Songs like "Shape of My Heart," which flows as gracefully as "I Want It That Way," prove that the Backstreet Boys do teen pop ballads better than anyone, but what's interesting about Black & Blue is how aggressively they protect their territory. Of course, it's relative protection, since they, like 'N Sync and Britney Spears, work with Max Martin, the man behind the biggest hits by all three artists. Consequently