Are there any free live concerts in Japan?

Going to Tokyo from June 24th to June 27th. Just wondering if there are any free live concerts where you can just watch without purchasing tickets.
It seems Michelle Branch , Vamps, Lisa, Granrodeo are doing live concerts.
Not sure if needed to purchase tickets there, or in advance or if it's free.
Granrodeo is my favorite singer though.

Of course there are free concerts everywhere. Yoyogi park always has some kind of event going on. When I was at Sunshine city last month in Ikebukuro there was some kind of girls idol group performing. Shibuya 109 has a stage, someone is a performing there regularly. I was at Daimaru building in Fukuoka there was a group called LOL performing to promote their new release.

Travelernow,

I'm afraid none of the artists you named are doing free performances during your stay. The closest would be Lisa doing free live on May 24 at Lazona Kawasaki. Also, foreign artists hardly do free performances in Japan. Hope you bump into one at a CD store or a mall, though.