Hi!
Don't worry, no problem!! :)
Mmmh, sadly I haven't found the subs for the whole concert... I only know that ohryouchipi has subbed the videos of the letters they read each other during the Wink Killer game... bur for the songs or for the greeetings or the final talk I haven't found anything :/

(but if you want a suggestion, watch it anyway! It's such a beautiful concert, and I've enjoyed it a lot even not understanding everything they were saying :) )