Harpvard Bridge hacks the space on Harvard Bridge, the bridge joining Back Bay and Cambridge. It takes advantage of the number of people who walk across the bridge between Boston and Cambridge while trailing their fingers along the railing by converting a segment of the rail into a digital harp. The harp has six strings, but it can support many more if one were to make a large public instillation of this project. The strings are standard guitar/harp strings and they produce the same sound as a guitar does. Each pair of strings is also fitted with a distance sensor, and they feed all their data back into a locked box holding an Arduino microprocessor board and speaker system. While the traditional strings are twanged, the speaker plays a complementary sound. Each pair of strings has a different sound. The hack turns trailing one's fingers along the rail into a fun, musical experience.