Dreamed I was tuning a pipe organ in a cathedral with no roof

I'm walking the ranks in a cathedral with no roof, and the sky is doing something impossible — dark blue at the bottom, grey at the top, like a page that was half-printed. Every pipe I touch sounds perfect until I move my hand away, then a full fifth flat. I keep walking back and forth between them, and the whole time the congregation is standing there without faces, patient, holding their hymnals the way you hold a basket you're not sure is empty.