Moving on, William R. Brophy in his Technical Studies for Solving Special Problems on the Horn notes that “the place at which the bell is closed” and complete closure of the bell are critical to stopped horn intonation.
Generally speaking this requires inserting the hand a bit farther into the bell than for normal “open” playing, though the size and shape of the hand and the size of the throat of the bell make generalizations difficult….
If we could remove the bones from the hand it would probably be easier to get the complete closure that is necessary. Since this is not possible the best that can be done is to try to make the hand as “un-boney” as possible, being sure that there are no knuckles protruding to keep from getting a complete closure.
Hand-stopping the horn is discussed from a more theoretical angle by Richard Merewether in The horn, the horn…. The acoustical question of what exactly is happening to the pitch of the horn when stopping the bell is an interesting one. From a practical standpoint, as the bell is closed slowly the pitch goes down but when it is closed very tightly the pitch will at least seem to rise; the impression as a player is that this is due to acoustically cutting off the end of the horn with the hand and shortening the instrument by a half step. Merewether takes the stand that this is only what appears to happen; to play a note is fully stopped one is actually lowering the next higher overtone to a half step above the previous pitch.
Barry Tuckwell in Playing the Horn notes on hand stopping that
It is the section around the thumb that causes most problems. This is made much worse if the thumb is made angular or the hand is put into rather than over the bell. Always remember that the hand should not be jammed tightly into the bell.
Very commonly the brass stopping mute is considered to be a substitute for hand stopping. Tuckwell also observes that,
The sound is not unlike hand stopping, but it is more direct and piercing. It can be used in certain circumstances as a substitute for the hand, particularly in the lower register, but care must be taken to camouflage the altogether more strident quality. This can be done by cupping the palm or putting some cloth or a handkerchief over the end. It is also possible to produce a more muffled sound by inserting the mute loosely and stopping up the end completely with the hand.
He feels that hand stopping and brass stopping mutes should not be used in combination unless there are specific low range issues, as “only an exceptionally proficient player can manage them with the hand.”
According to Frøydis Ree Wekre in Thoughts on Playing the Horn Well, daily practice (“several minutes”) of stopped horn is beneficial for these reasons.
Firstly, the quality of your stopped horn playing will improve, regarding intonation, steadiness and sound. Secondly, it is efficient training for EXHALING. Big quantities of air at high speed are necessary, especially in the lower range. Prior to that, of course, a huge INHALING is necessary. Since GOOD INTONATION is a MUST, the lips and other facial muscles will get an effective workout. Loud stopped horn playing is physically somewhat different from normal playing. It demands more effort. Thus practising it can give more strength in a shorter amount of time.
Have you practiced stopped horn yet today? Next weekend we will conclude the series on stopped horn.