Tight high notes

[solidshi8]

I’m currently playing a Shires Alessi Custom Series horn. Lately, I’ve noticed that hitting high notes (above F) requires more effort. I’ve checked the water key and valve section, and pulled the tuning slide to confirm the ‘pop’ sound—everything seems normal. What might be causing this issue?

[harrisonreed]

Assuming it's the horn, could be scale buildup in the crook, tuning slide, misalignment of the valve -- any number of things.

Could be some crazy things too. One time I had the slide crook peg rubber cover somehow inside my F attachment... Made me wonder why none of my notes with the valve were working during the gig... Finally blew that sucker out the bell trying to *force* the low note to speak. Shot way out off the stage.