Late to the party, but the one who arranged it is the guy behind the piano. He's a very well known film and videogame composer. His name is Petri Alanko. He was also responsible for the incredible Alan Wake score. Brilliant composer! The part at 2:47 is a modulation technique that's absolutely stunning. That's the part that makes me emotional, even after hearing it for the 1000th time. What's important to know is that usually, dance songs played by the orchestra is just "beats with strings on top". This isn't. This is actually arranged in a way that it is it's own composition in it's own right. This is proper composing/arranging. This is a textbook example.
Saltwater is built on Theme From Harry's Game, but this piece clearly follows the chordprogression of Saltwater which differs from Theme From Harry's Game.
