But now that I think about it almost all of Britney's songs are inspirational in some way (not just in the emotional/dramatic sense of the word).
Every song Britney has can inspire you to Dance , Sing, Cry, Feel more Confident etc.
Also, it's not a song but a vh1 documentary.
It's called "Driven" and it's about Britney's road to fame and all the proffessionals who met her along the way.
Well, they all agree on one point, the extraodinary potential of Britney and how impressed they were with her talents and efforts to reach her dream.
Britney has many songs that could inspire you! 3 inspires me 
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