I am constantly surprised at how differently I approach intonation practice than so many other people. I was in a flute choir rehearsal last week and the director was working on a passage where the intonation was not working. She was working on just 3 notes that a section had to play, D3-F3-D3. They got the first two notes going pretty well, but they could not come back to the second D3 from the F3. I made a remark to myself that the problem was not the notes themselves, it was that the descending interval was not the same size as the ascending interval. The flutist next to me heard and said something like “Wow, you really analyzed that on a different level!”
I do not have such great ears that I was hearing what each player was doing. It only makes sense that if they can play D3-F3 with and be in tune with each other and don’t get back to the D3 together, they have done something differently. The second D3 is different from the first and the second interval is a different size than the first.
To me, this is part of learning to play in tune, not so much that the individual notes are at the ‘correct’ frequency, but that the intervals are the proper size. Start by not stretching the octaves, don’t go sharper as you ascend or flatter as you descend. All D’s are proportional to each other, make them sound that way. Same for all E’s, F’s, C#’s, etc. So simple, so difficult, and so necessary. If the director had told the section to play the second D3 the same as the first, it could have been a much simpler fix, rather than saying ‘you are sharp and you are flat’ etc. Intonation is relative. Start from note and tune every other note in relation to that one.