Conversation so far:
Is Pale Green Ghosts a song?
Yes, a song and an album by John Grant.
What was a single from the Pale Green Ghosts album?
Black Belt
Was the Pale Green Ghosts album well received?
Pale Green Ghosts was released in March 2013 to critical acclaim. Pale Green Ghosts was Rough Trade Records Album Of The Year.
Did any guests appear on the Pale Green Ghosts album?
Sinéad O'Connor was guest vocalist on three of the tracks, including It Doesn't Matter To Him.

Question: Were they friends?
Self-contained rewrite: Were John Grant and Sinéad O'Connor friends?