No idea, but "The title of the series comes from the Japanese word for light music, keiongaku, but in the Japanese context is similar to pop music."
"The characters of K-On! have surnames derived from members of the Japanese bands P-Model and The Pillows."
http://en.wikipedia.org/wiki/K-On!
"P-Model was a Japanese techno-pop band"
"The Pillows (styled as the pillows) are a Japanese alternative rock band."