Richard Merewether, as a horn designer, has an interesting perspective on hand position in The horn, the horn….
In the day-to-day activity of assisting players of many nationalities and every stage of attainment in the choice of an instrument (whether of our own or other make), PAXMAN are in a unique position to have observed over many years exactly what is involved in moving from one type of horn to another. Most noticeable are the widely-differing modes of right hand placement in the bell-throat … and the striking effect this can have upon a player’s performance when moving from a small-bore to a larger, or from a conventional instrument to a Descant-horn.
From this observation has emerged the clear fact that, whereas a sketchy or … non-existent hand-presence may serve for the smallest-throated bells, ALL instruments perform better, in tone and intonation over their widest range, with the use of one particular method—that traditionally employed by the great XIXth-century hand-horn virtuosi. PAXMAN make no claim to have discovered this—only to have confirmed its efficacy and importance by establishing the acoustic reasons for it.
This type of hand position is effective on all sizes of bells: Merewether used this illustration, reprinted from the Kling method, and further explained,
This represents the hand-position for normal ‘open’ playing, but note that it is also an ideal starting-posture for instantly closing the bell, merely by bringing the heel of the hand over to the nearer side while the nails and backs of the fingers remain against the further wall of the bell; this is essential for a good hand-stopping technique. Observe also that no part of the thumb other than the nail and top knuckle—certainly not the base of the thumb—is held against the metal…. It should be noted too, that the thumb-tip must be consciously lifted up to the base of the forefinger to close any gap there, and not merely be suffered to lie alongside it. Unfortunately some illustrated Methods are published seemingly condoning this fault, which will almost certainly bring the entire side of the hand (all of the forefinger and thumb) into contact with the bell-wall, and the consequent difficulties of intonation for many types of horn.
The larger bell instruments he observed were more sensitive to an incorrect hand position than were small bell instruments, and that any gaps between fingers and “floating movements” of the hand in the bell do have an adverse effect on the high range. He gives the following as an example that may be used to show the validity of this theory of a correct hand position producing a more stable high range.
Consider the horn played with a careless hand-placement (or none whatever) which will nonetheless give reasonably-centered notes at least as far up as the twelfth harmonic …. the addition of further harmonics up as far as the 24th, through a studied and exact right-hand position, must add greatly to the stability all over the range, besides enhancing the horn’s timbre by bringing in all its high-frequency potential as available and evocable overtones.
I discuss this last quote further in this post. The image was linked from the library at Osmun.com, as they have posted substantial excerpts from The horn, the horn… on their website. The section I have quoted is posted here.