Gunther Schuller addressed the topic of the lip trill in Horn Technique from the practical standpoint of viewing it “more as a means of obtaining lip flexibility than for the sake of developing the trill itself, although that will, of course, be very useful at times.” In terms of how to practice trills, he recommends slow work on a pattern similar to that of Farkas.
The basic thing to realize about lip trills is that the two notes of any trill are not produced differently than in a slow slur. The process is exactly the same: a slight closing of the lip opening and an equally slight increase of air to obtain the upper note; the opposite to return to the initial lower note….
It is suggested that when the trill is first practised, the upper note be slightly breath-accented (as in the syllable ‘hah’). This will facilitate accurate timing of the slur, and will assure the proper amount of air.
…there are no short cuts to learning the lip trill; any other methods of trilling (except for the use of valves, which is permissible in most orchestral situations) are musically not valid. The shaking of the horn or various ‘gargling’ methods produce[s] unsatisfactory or ugly results.
One aspect of trilling is often neglected. This is the problem of starting a trill fast and loud immediately. I therefore recommend that at a reasonably advanced stage of trill practising—and only then—the sudden abrupt trill be practised as well.
One other method of working on trills is advocated for work on “really recalcitrant” trills, that of aiming for the half step between the notes of the trill. For example for a F to G trill if you aim at a F# it will put the lips in the position where a “very slight shifting to either side will produce the desired F and G, and will eliminate the necessity of ‘traveling back and for the entire route. It is like sitting on the fulcrum of a see-saw.”
Milan Yancich in A Practical Guide to French Horn Playing presents a variety of trill exercises. He feels that trill practice is of value in “developing flexibility of the lip.”
William C. Robinson mirrors that thought in An Illustrated Advanced Method for French Horn Playing, and with it notes that “Lip trills should be practiced each day for very short periods; best results are obtained by using a definite rhythmic pattern.”
Fred Fox in Essentials of Brass Playing suggests for trills “finding the precise point where the note changes, and hovering just a hair above and below the change point.” He comments that
If there is too great a distance between the notes then too much time is lost traveling that distance and a trill—which is a very quick oscillation between two notes—can never be achieved. Once this technique is mastered on an interval of a second, it then becomes a comparatively simple matter to locate the break point on lip intervals of a third, or a fourth, and by again hovering just above and below the break points, get an effective lip trill on these intervals as well.
Next up in this series are quotes from books with longer sections of text related to trills.