From that most xcellent blog We Make Money Not Art:

Interactions under the city

undersound is an interface that allows you to listen to, distribute and affect the flow of music on your mobile phone while you're travelling in the underground.

The project imagines that you will be able to add music to the system at upload points in the ticket halls, and download tracks on the platforms. Because of the architectural configuration of the stations undersound users would have to congregate at certain locations for the purpose of interacting with the system.

Each track in the system is tagged with its place of origin (the station where it was uploaded) and this information is visible as the track is being played. This may trigger musings around your personal relationship to that place.

While in the carriages of the tube, you can browse undersound music of other people in range (that idea was inspired by tunA). You can see when a track has been in the system, the number of times it has been played, the number of people who have played it, etc. You can browse through other's tracks anonymously, but if you decide to download a song from someone else an alert will be triggered on their phone letting them know that you are grabbing one of their tracks.

A project by Arianna Bassoli, Johanna Brewer and Karen Martin.

Via coin-operated.

Another nice art project for the metro:

In unspoken_series, performers done a custom-made construction vest embedded with red and green LEDs to permit the display of up to 24 characters.

The artist programmes messages on the front and back of the vest, revealing facts, thoughts or ideas that the wearer would otherwise not pronounce in public. For example, the vests worn in the metro could display at once humorous and confrontational messages such as: “Took my seat...I am not happy!” or in an art gallery it could be "This is crap! ...are you happy?”

People who happen to be in the metro become the audience. The vests become the starting point of conversations about issues around the specific city the wearer is traveling to or from, about the main target audience he or she is exposed to, and general concerns in public space.

Video.

A work by Hoyun Son whose website also features a very funny parody of Speech Recognition Technology (video).

Currently on view at Sartorial Flux, a show curated by Valerie LaMontagne, at the A + D Gallery in Chicago until October 21st.

Deeper under the ground: For sale: Britain’s underground city; Tokyo's underground farm; Frame-by-frame underground ads; Cast Off stages knit-ins on the London Underground, occupying a carriage and knitting around the Circle line; Locker art show; parasite and Chiho Aoshima in the London underground.