There are several instruments that have music written for them primarily in bass clef, but commonly change to tenor clef for a higher passages. In particular, I am interested in:
- Euphonium, Tuba
- Cello, & Contrabass
While changing clefs does reduce leger lines, I don't believe that this is a good reason to use the tenor clef. The tenor clef is better used to indicate a higher register of the instrument is being employed — this is a more functional and meaningful use of notation.
My question goes to when is it appropriate to use the tenor clef:
— (For each instrument) What are the functionally useful register boundaries (to change clef), and how are these determined?
Theses boundaries will not be at identical points for each instrument, but there should be some kind of rule. For wind and brass instruments: something to do with which partial is being employed. For string instruments: something to do with the hand position and the strings being used.
I understand that for brass and string instruments there will be some overlap in the registers due to alternative fingerings/positions for many notes.
(Obviously a musical phrase may span across these boundaries — so compromises will be made to avoid changing clef within a phrase. But I wish to consider the ideal placement of a single note/pitch, with a particular fingering/position.)