Attending an Ayu concert without tickets??

[Emperatriz Ayumi]

Hello dear people from the forum. I need some help, this december I am going to Japan and I would love to be able to buy a ticket for the CDL. But in the case I can't buy one, can I, at least, stay outside Yoyogi and be able to listen to her singing live?? Or even being outside the stadium you can't listen to the music??

Thanks a lot!!