Nick Mason didn't play on "The Narrow Way.

None. It’s a David Gilmour solo piece — he played everything: guitar, bass, drums, keyboards, and sang. Nick Mason’s solo track on Ummagumma is “The Grand Vizier’s Garden Party,” which is all him (mostly percussion and tape loops).

So if you’re tracking who played what on that album, “The Narrow Way” is pure Gilmour. No drums from Mason, no backup, nothing. Just David doing his thing for 12 minutes.