Major Shire Variants:
The White Tree
Into The West
Merry and Pippin
Arwen's music keeps changing as the movies progress. This is the only Arwen music I could find that appears in more than one scene. Why Shore gives us different music every time we see Arwen and Aragorn together instead of giving us an explicit theme for their love I cannot say.
I have no idea what was in Shore's head of course, but I know what I like about this: The relationship of Aragorn and Arwen is so richly endowed with the history of Middle Earth and with the sublime joy and loss of their own love that it's as though every encounter is exploring a different resonance. In this succession of themes there is perhaps a sense of the pageant of the past that flows to and between them -- and their own tragic but joyous future.
I'm not sure I quite buy that, but I offer it up here as one intelligent observer's point of view.
||Arwen appears in the forest.
||Arwen picks up Frodo after the river overflows: "What grace is given me..."
||Arwen appears at Aragorn's coronation.