So, you've got a song here in F that tonicizes both the dominant harmony of C (in the rocking part of the verse - "If the program director don't want it," etc.) and the subdominant harmony of Bb (on the title words "overnight sensation" that come at the very end of the verse). I'm not a piano player, but the solo piano line that occurs after Bb is tonicized seems to end on a bit of a bVII harmony. It's that Ab major harmony that functions the second time through as the pivot chord that leads to the key center of Db major for the bridge (Ab being the dominant of Db).
Here, though, is where the song does what is possibly my favorite thing. It's necessary to call the key center here C# instead of Db because the chords move from I (C#) to bVII (B). Now, of course, we just had bVII harmony eleven seconds earlier in a key (Bb) very remote from where we are now. There's an incredible continuity from this immediate repetition of the same harmonic vocabulary, but this moment is also rich in how it balances simple and complex elements. On the one hand, we've not only modulated (cleverly) to a remote key, but we're using unconventional chords once we get there. On the other hand, a I-bVII chord progression is actually an incredibly simple thing, and only unconventional in this context: a bridge where you'd think that we've just modulated a great distance and maybe we need to start thinking about getting back right away!
But they don't. Raspberries drag it out so sweetly with this chord, giving Carmen the time frame ("Amazing how success has been ignoring me so lo-o-o-o-ong") to state his plight.