There are only 4-12 "networks" in Japan... the rest of the channels are pay-to-view sattelite channels: which I doubt you're going to be able to stream for free (at least legally). There are, however, music shows on each of the channels: "Music Station" (TV Tokyo) and "Hey Hey Hey Music Champ" (I don't remember the channel) are the most popular. I don't watch either any more but did when I was into music. Pop Jam may also still be on NHK... and NHK also has "Kohaku Uta-gassen" every New Year's Eve... which is four hours solid of performances by everyone who's been remotely popular in the last year.
I'm afraid I don't have times for any of this... but if you go to the channel's websites, you can search for air times through the programs' pages.
NHK has an excellent children's block daily - Nihongo de Asobo, Inai Inai Baa, Okaasan to Isshou, Karada de Asobo, Quintet, etc... Think along the lines of Japanese Sesame Street. I owe most of my early Japanese exposure to NHK's kyouiku terebi