Do notes slot easier with slides all the way in or out?

[Leto Cruise]

Despite their tuning issues, do notes around F in the staff and up slot easier with the slides pushed all the way in, or all the way out? I'm aware that not all horns are the same when it comes to this, but if the slides are pushed completely in, shouldn't this mean that it will take less air to produce those higher notes with less force? Or is it the other way around? Help is welcomed!

[djwesp]

I imagine that these "slots" you speak of are nothing more than the horn seeking out its harmonic series.

The horn wants to play to it, it gravitates towards the nearest one to your buzz. I don't think that altering the slides will alter how well it slots, just where it slots to.

[iiipopes]

In a word, no. Amount of air has very little to do with relative slotting, as the resonance of the instrument has more to do with static wave theory, including nodes and anti-nodes, than it does with flow theory. Now, if the slide is pulled out so that the change in diameter of the tubing from the inner to the outer tubing or vice versa just happens to hit on a node or antinode, then that may cause an intonation issue with that one particular note, as it does on some Krupse french horns.

As the chart above shows, each partial, although an integer multiple of the fundamental pitch, gets closer and closer together: octave, then perfect fifth, perfect fourth, major third, minor third, minor third, major second, major second, etc. So it's more of embouchure control for which partial to slot rather than the slotting of the horn itself.

Also, depending on the taper of the bugle, throat and bell flare, above a certain harmonic, because the rest of the horn, bracings, valve block, etc., gets in the way, the "terminal node" can't form, and the horn stops resonating pitch and becomes a fancy megaphone. It's the same reason you see screaming trumpet players playing in the stratosphere with valves optional: it's all chops and no horn.