What is "klatter"

Klatter is the third collaborative studio album and sixth release by the Japanese experimental rock band Boris and Japanese noise musician Merzbow. The album features re-recorded versions of "Akuma no Uta" and "Naki Kyoku" from Akuma no Uta, and a cover of "Jane-Session" by the German progressive rock group Jane. It was originally planned for release on Troubleman Unlimited in 2007 under the unconfirmed title Mellow Peak, but for unknown reasons it did not happen.