Global String (images above), created by Atau Tanaka and Kasper Toeplitz, is a multi-site network musical instrument connected through the internet and used for performance and installation (see diagram below):

It is a musical instrument where the network is the resonating body of the instrument, by use of a real time sound synthesis server…The concept is to create a musical string (like the string of a guitar or violin) that spans the world. Its resonance circles the globe, allowing musical communication and collaboration among the people at each site.

Re-seen in the post here, Rope Instruments.

This relates to earlier posts on lines including Line by Andrew Neuman, Oneline.com and Liners.