White of the Eye (Parts 1-34)

This was a film score by, I believe, Nick Mason and Rick Fenn, but maybe somebody else and Nick. It's interesting to say the least, and it's 34 parts long.

Yup, it was Rick Fenn.

how long is this song?

Approximately 50 minutes. However, it's not a "song" as much as it is the score the a film. It can be found on the bootleg "A Tree Full Of Secrets," where the compiler explains that he simply snipped the parts of the movie that had Floyd music in them.