There are only about 5 songs that they wrote but there are a lot of covers for other songs they did.
$20
All of Glee's biggest hits, such as Keep Holding On and Don't Stop Believin'.
They are referred to as 'TV Show Tunes'.
Yes they get permission for all their songs
Yes, all the characters sing the songs.
yes
Silly Love Songs - Glee - was created on 2011-02-08.
As of right now there have been no Green Day songs on Glee.
i am not sure but i love glee
its not really necessary to look for unlockables. All you have to do is sing the songs on the game and certain songs let you unlock the songs without the codes.
http://www.buddytv.com/articles/glee/listen-to-the-music-from-glee-32768.aspx
no.