An interesting question recently came in from a reader, on the topic of the arpeggio patterns used in warm-up exercises. An early teacher of the person writing the question had basically instilled into their mind to never ever play arpeggios using, if you were playing open F horn, the Bb on the middle line (or A fingered with the second valve, etc.), as it is out of tune. A later teacher however made use of exercises that included that note. Who was correct?
My short answer is I have used exercises with that flat harmonic for years but I can also see the point the early teacher was making.
I have observed two schools of thought on warm-up exercises in general. Some people use patterns on harmonics which use fingerings for notes that we don’t normally use. The idea is it makes it harder and when you shift to normal fingerings it makes it easier, and you will be more accurate for the effort. A pattern such as the one here is an example of this.
The other school of thought is always use your normal fingerings, never use non-standard fingerings because it will make you less accurate, you need to always play on the normal fingering to really get the feel of the note and where to put it.
Then we get to the Bb question on the open F horn. The teacher had a point because it is out of tune and playing that note could train you to place notes incorrectly. But personally I do harmonic series patterns with that note almost every day in my most typical warm-up at present. It is early in the routine and I use those exercises to focus in on the embouchure and control early in my warm-up. Then I switch to real fingerings on other patterns.
Hopefully I get the best of both worlds, but again I can see the point. Ultimately either tactic gets at development of accuracy through the warm-up, and it will be one to be decided on an individual basis where you are most comfortable in terms of F horn versus standard fingerings and also the Bb harmonic or no Bb.