The structure, called Ark Nova, was designed by Japanese architect Arata Isozaki and British sculptor Anish Kapoor. It's a mere 0.63 millimeters (0.02 inches) thin, but when fully inflated it will house 500 music lovers on seats carved from cedar trees damaged in the floods.
If you insist on knowing the dimensions: the 2,000 square meters of "PVC-coated polyester" material rises to 18 meters high by 29 meters wide by 36 meters long, according to the organizers.
The performances start with a workshop in Matsushima by the Tohoku Youth Orchestra, and on Saturday night the Sendai Philharmonic Orchestra strikes up Beethoven's Symphony No. 6.
The ensuing weeks will include traditional Japanese Kabuki theater, the Jozenji Jazz Street Festival, and the Lucerne Festival Orchestra - all in Matsushima for the time being, but the idea is to eventually deflate, move and then soar all over again elsewhere.
On Saturday, Gustavo Gimeno will conduct. I'm not sure what he's planning for an encore. How about the old rap tune Pump it Up?