Condolences to you Dan, so sorry mate...
But man, I had no idea Dan couldn't sustain the harsh vocals for very long...Crimson 1 & 2 are so brutal and Dan is one of my favourite growlers ever...I would have never believed it if I didn't hear it from the man himself!
Actually, Mikael Akerfeldt (Opeth) singed on Crimson, and Rogga made the most vocals on Crimson II