Blue Man Fans

On the video Mashable did on BMG Mark Frankel said that "[The PVC] was used to its utmost capacity of durability" and the new one " it's bright clear and loud and and um it sounds- it sounds like it was initially intended to sound now". How exactly do they come out of tune? if that's what he's talking about because the old ones looked so dirty.

Does the chemistry or structure of the PVC material change over time? Maybe from paint splattering and degrading all over it as seen at 2:22? Maybe the temperature and humidity expanding and contracting the material so much that it deforms permanently? Maybe the material absorbed or lost too much moisture over years?

https://www.youtube.com/watch?v=3XqRJRCSQzA

The structural integrity of the PVC’s themselves wears down over time. Keep in mind, the original set was in the theater something like 20 plus years. Night after night, continual slapping with paddles, probably at the time of this video some 16,000 performances. I’m almost certain the glue was breaking down, some of the structure itself was rusting, the joints were more than likely cracked or barely hanging on. All these factors combines, the set was more than likely deteriorating pretty badly. Factor in climate as well, as the harsh NYC’s are bitter cold and the air is super dry. PVC ideal climate is moderate at best.