This website is quite fun in that it's basically a pop quiz on the guys' songs which's spilt into 3 levels of difficulty :
http://music-kentei.net/kentei.html/256247751/1/10/0
10 songs easy level
10 songs advanced level
100 songs expert level
Everytime any of the 3 link/s are clicked , a different set of songs' preview snippets (ranging from single songs to B-sides to album tracks) will be uploaded on the website .
Seeing that I've been in the guys' fandom for a very long time , this's extremely very easy pickings for me , be it any level I attempt to do x)