Yes, thats the guy! I saw him too, but couldn't remember his name. Now that you mention it, you were the big guy with glasses at the back left of the hall as well (on Sunday) weren't you. Sano san was just in front of you!
(for those who don't know) Sano Shiro is a relatively famous actor in Japan, and appears in many places on film and video. I have to say "relatively", as I saw him, and knew him, but couldn't place him in my memory! I said to Rob at the gig on Monday that there was a famous person in the house on Sunday - but now thanks to Poyns (or his wife??), I can reveal his identity!
Indeed his website does mention a great evening, especially the choice of songs, and also the combination of John and Louis being good. He moentioned John's voice being of fine quality, something my wife noted as well, but something I take for granted!
For the Japanese in the forum, the blog he wrote is
here. As a side line (read on Mr Shiro's blog), the director of the latest
Ultraman Movie was with him. Maybe that means little to many here, but Japanese children (mainly boys) have to go through an Ultraman stage in their childhood - my son is going through it now (age 7)!