Finally got my answer from the composer himself --

1.30 - 1.41 is the opening of Bach's G major Prelude, played by Yo-Yo Ma. There are additional string parts added to that section. 1.41 - 2.23 is an orchestral piece 'Soloist Finale' written especially for the trailer, which ends (2.23) with the last 2 bars of the G major prelude (again Yo-Yo Ma). The reason it all sounds like one piece is because the orchestral middle was designed to link the 2 bits of Bach together.