An ultrasonic keyboard was designed specifically for a cat's sense of hearing and plays frequencies feline music in , so not only the keyboard player plays in human frequencies, but your cat can also enjoy them. An team vets enthusiastic of , sound artists and scientists created the keyboard. It is fed through an iPad which converts the frequencies that people can hear into frequencies that only cats can hear. The team also created the keyboard as part of an censorship anti-Internet campaign called the Pussy Cat Riot. The first live show was a protest performance to an audience of cats playing national anthems of countries that heavily censor the Internet.