I went down to the Renwick Gallery in DC a few days ago to see the exhibit WONDER, which lived up to its name. While in the area, I got to listen to the album/app/experience "The National Mall" by DC-based Bluebrain.
In the physical world, the National Mall is a wide expanse of open space anchored by the Capitol building to the East and the Lincoln Memorial to the West, surrounded by iconic Smithsonian museums and US civic institutions. The National Mall is also location-aware musical composition, a self-contained iOS app that uses your GPS to determine your location and only plays when you're on the Mall.
As you walk along the Mall, the ambient soundtrack shifts to reflect your changing location, blending seamlessly from one locale to another. The promo video includes some of the musical tracks in their appropriate locations. It makes for a lovely and immersive experience.