The interval between C and E is a major third.
この曲は音程の跳躍が難しい。
The wide intervals in this piece are difficult.
Colloquial use for the pitch or key of a song, often in contexts like singing or tuning. Less formal than sense 1.
音程が外れてるよ。
You're off pitch.
もう少し音程を高くして歌ってみて。
Try singing it in a slightly higher key.
She can hit the right pitch even in difficult songs.
Both of their singing voices are perfectly in tune.
That phrase's pitch is too high to sing comfortably.
You measure the interval precisely with an instrument tuner.