Conversation so far:
When was Pink Floyd's album Wish You Were Here released?
Wish You Were Here was released on September 12, 1975.
Did Pink Floyd go on tour for Wish You Were Here?
The band played much of Wish You Were Here on 5 July 1975 at the Knebworth music festival.
Did Pink Floyd have any problems when producing Wish You Were Here?
Roger Waters struggled to record the vocals for Have a Cigar, requiring several takes to perform an acceptable version. His problems stemmed in part from stresses placed upon his voice.

Question: Why were they having trouble?
Self-contained rewrite: Why were the members of Pink Floyd having trouble?