Why does my horn play in tune low but sharp or flat up high?

Question

Low notes are fine but the upper register drifts. Is it me or the horn?

Accepted Answer

This is often a sign of an embouchure or air-support issue, but it can also point to a setup problem — pad height, neck fit, or even a slightly bent body affecting the upper partials. If it's consistent across players, it's worth a technical check, not just practice.