I’d say that I probably enjoy about half of the songs on the radio today. The other half either make me feel less intelligent (e.g. Replay by Iyaz) or fall short of my desired melodic quota (e.g. Imma Be by Black Eyed Peas; I hate this song).
I don’t think I can easily describe what’s in my tastes, but in general, most of the songs I like capitalize on the ever-popular I-V-vi-IV or i-VI-III-VII chord progressions somewhere in the chorus or refrain (e.g. Lifehouse‘s Halfway Gone, Taylor Swift‘s Love Story, Lady Gaga‘s Poker Face). Actually, the refrain in Replay uses the latter chord progression too, but I just can’t stand that part where he makes baby sounds and starts talking about his iPod. Anyway, the point is: we’ve got a lot of songs on the radio, and they’re all winning hearts with some of the same, tried-and-true musical constructs.
Not one to be caught going with the flow though, Britney occasionally throws a few little curveballs into the mix to give her songs an exotic or oddball quality. In If U Seek Amy, she sticks a B-flat into the tail end of the refrain, lowering the second scale degree a half-step and thereby giving the phrase a Phrygian-like modal inflection.
From its beginning, the song clearly establishes A minor as the home key, though we don’t actually hear a B-natural until right before the refrain is first sung. As if to draw more attention to themselves too, the B-natural and B-flat both appear in a conspicuous rhythmic context: a three-against-two hemiola (i.e. three quarter notes overlaid on the third and fourth beats of the last measure, as depicted above).
Anyway, the modern Phrygian mode is not so different from the natural minor (Aeolian) mode, as it differs only in the aforementioned second scale degree. And so it’s not completely jarring when at the end of this descending line one hears a pitch that does not belong to the tonic key. It’s like in the song 3, when Britney sings an A-natural instead of an A-flat (the third scale degree) to put the phrase momentarily in a major mode. The effect is mysterious. Furtive. Teasing. Britney.