The following quote is taken from the wikipedia page about Scream Thy Last Scream:
The song features several changes in tempo, a sped-up double-tracked vocal part by Barrett, while drummer Nick Mason simultaneously sings the normal part (one of only 4 moments he ever sang on a Floyd record)
Which are the other three tracks in which Mason sings in a Pink Floyd record? Wikipedia quotes Inside Out, written by Mason himself, as a source for the number four, so the answer to my question might also be in there, but I don't have a copy available at the moment.
