In general the topic of muted horn appears to have been of no great concern for Farkas from a technical standpoint (“with proper practice, the change in resistance caused by the mute will not be upsetting”), but certainly the mutes of the 1950s must have required more adjustments of corks than we expect to see today, and there was the musical side of things to address as well. Quoting from The Art of French Horn Playing,
First let us clarify the myriad terms used to denote muting or hand-stopping. The is a distinct difference between the sound of a muted horn note and a hand-stopped note, as most composers are well aware; but players are inclined to treat this difference lightly and use whichever method suits their convenience. I believe that this is a rather serious mistake and, to some composers, a downright affront.
Farkas gives an overview of some of the more confusing notations of Ravel and Debussy and offered a short list of terms related to muted and stopped horn. (I have a longer list here, with the most important terms related to muted and stopped horn marked). Farkas also explains that the terms schmetternd and cuivre “refer only to the player’s ability to get a hard, brassy sound on the open horn by unduly tightening the embouchure with a ‘smile’ and forcing the tone.”
While he has several practical notes on muting (“It is not necessary to jam or grind the mute in” for example) Gunther Schuller in Horn Technique is especially concerned with the musical side of the horn mute question in the orchestra. In explaining this he takes the opportunity to chastise composers who don’t understand the effects requested in their own music.
Many composers are not very clear about the difference in the sounds produced by using a mute and that of hand muting (or hand stopping). Not knowing the difference, they write in their scores simply ‘muted’ or the equivalent in their own language. Often they write ‘con sordino’ when they really expect hand muting; and vice versa. Many players also assume that the composer and the conductor do not know the difference, and therefore do whatever comes easiest, which is usually to put a mute in the bell. A few composers, however, like Wagner, Mahler, Ravel, Debussy, Respighi, and Stravinsky, do insist on the differences between the two forms of muting.
Schuller also adds this note.
One final note on using a mute. The nature and construction of mutes cause the sound waves to be deflected partly into the cone of the mute and partly back into the instrument. This ‘backing up’ of the vibrating air column can have a disturbing effect upon the player’s lips. It accounts for the difficulty players often find in attacking a muted note with a clear attack and unwavering tone. It is therefore necessary, in attacking muted notes, to brace one’s lips against the rebounding air column, as one would brace one’s self in surf against an oncoming wave.
As to non-transposing mutes Harry Berv in A Creative Approach to the French Horn feels that mutes made of fiber produce “a more mellow, descriptive sound” than do mutes of plastic, cardboard, or metal.
Barry Tuckwell notes in Playing the Horn that
A really good mute is exceedingly rare: most produce altogether too open a sound. This may sometimes be improved by cutting down the corks so that the mute can be fitted further into the bell.
I believe speaking generally that the consistency and quality of horn mutes used by professionals has gone up over those used when the above books were written. As to my recommendations today,
There are a lot of mutes on the market, each with a unique shade of tonal color and slightly different playing qualities. If you can, try the mute before you buy it–especially try the low range, which on some mutes is quite poor. In general many professional players in the USA prefer “Rittich” style mutes, the ones that look like a tall cone. I would by choice recommend a tunable version of this type of mute. While it may make sense to purchase a cheap mute for a school program, for personal use always look for something up the ladder in terms of quality.
Many students today wonder what is a Rittich style mute, or why this name became associated with this type of mute, such as seen in this photo. Nicholas Smith offers this background in an article based on his 1980 dissertation,
In surveying todays professional players as to what their mute preference is, the name Eugene Rittich of Toronto, Canada seems to be mentioned more than any other. Mr. Rittich has been for many years Co-Principal of the Toronto Symphony and his experimentation with mutes began as a result of his dissatisfaction with what was available.
He began working in 1962 to try and achieve better intonation and response from the then popular cone on cylinder mute shape. This failed to produce the results he wanted, so he experimented with a simple cone shape which achieved better results. Before long, he was receiving so many requests for copies of his design, that he decided to produce them for sale. Since that time (1967), he has worked to find the best combination of the many variables found in a mutes dimensions. These include taper and length of the cone, top hole diameter, diameter of the inner cylinder, placement, width, and thickness of corks, and the materials from which the mute is made.
The Rittich mute has an adjustable length inner cylinder for fine tuning the mute to any horn. Although this feature isnt new, it is probably the most successful application of a tunable mechanism on a mute to date. The success of his design is evident by the large number of copies being presently produced by other manufacturers.
Besides keeping a mute in the trunk of your car, my only other small note would be that it is worth having several mutes. In particular I find that for brass quintet a mute with a brighter tone is desirable, brighter than that of the typical orchestral mute.
Next up in this series is the topic of stopped horn.