“The most open, freely speaking, resonant sound
tone production is based on speed of the bow” 
Practicing the son filé bowing is the best way to learn how to control bow speed. Many great violin masters write about and advocate the use of specific exercises in teaching this element of good tone production. Simon Fischer provides a great number of exercises for mastering this important bow control technique in his book, Basics: 300 Exercises and Practice Routines for the Violin.  Ivan Galamian also includes exercises in his book, Principles of Violin Playing and Teaching.  Mastering the technique of playing long, sustained notes with varying dynamics is a violinist’s oldest, “medium for the study of tone production and bow control.”  Galamian associates this with, “what breath control is for a singer — the ability to sing long phrases without having to interrupt them for a new breath — bow control in a long, sustained stroke is for the violinist — the ability to sustain a long tone or musical phrase without having to change bow.”  Carl Flesch uses son filé exercises in his book, The Art of Violin Playing, and suggests that adding emphases (forte and piano) can provide excellent study material for producing a variety of nuances.  In keeping with these great masters, I have devised, for my own teaching, some very easy bow speed exercises that beginning string students can play. I have found these exercises (described below) to be very successful, and they allow the students to have a little fun, at the same time.
Simon Fischer: Long, Slow, Sustained Bows, the Son Filé Bowing
Simon Fischer suggests the following exercise be practiced using various note lengths, various string crossings, and playing them in various positions. This exercise should be played as slowly as possible, with a sixteenth note equal to 40 – 60 metronome beats. The entire exercise needs to be bowed close to the bridge, including the piano sections. 
Sixteenth note = 40 – 60 (play on each string)
Ivan Galamian: The Son Filé Bow Exercise
Ivan Galamian teaches that these bow exercises need to be practiced on all, “open strings, on scales singly and in double stops . . . in every dynamic from piano to forte and with the dynamic variations” shown below.  The tempo should be as slow as possible, and should remain the same throughout each variation. The goal is to begin at a slower tempo each time you repeat the exercise. It is also important for a violinist to listen for the “quality of the sound produced, its resistance, and its evenness.”  Galamian writes that it is important to educate the fingers on the bow, especially the index finger, to be sensitive, “to the resistance of the strings and thereby of gaging  the pressure and friction exerted by the bow on the strings.” 
Carl Flesch: Long Bows, Sons Filés, or “Spun Tones”
Carl Flesch writes about the importance of practicing long bows, referring to the bowing, sons filés, as spun tones. These are to be played on the “correct” contact point, with no sliding between one another. Further, Flesch instructs that the exercise is to be played with as light a bow as possible on the string, thus producing only a “mere breath” of a tone. The length of the notes should be “6 to 20 seconds in forte, and 12 to 60 seconds in pianissimo. The duration of the exercise as a whole, should certainly not exceed 15 minutes.” Flesch adds that although this exercise is one of the most boring in developing right arm technique, it is one of the most beneficial as well. 
Cheri Collins: Beginning Bow Speed Exercises
Learning bow speed can begin early in a string player’s development. Having students learn how to make their bow move slowly between the frog and the tip (minimal bow speed) can help them achieve more bow control when slurs are introduced, encourage students to watch their bow, and help them begin to feel how to control the bow’s speed. Beginning students always feel that they are running out of bow, and reminding them that their bow is really very long will help with this problem.
Exercise I: How High Can We Count?
- Have students play a down-bow very slowly while the teacher counts aloud up to twenty.
- Repeat the exercise, increasing the count by increments of five or ten, each time. Remind students to keep their bow moving throughout the entire exercise.
Another excellent exercise using bow speed for teaching good tone production in a beginning heterogeneous group, begins with counting aloud with a steady beat (metronome: sixty beats per minute) while playing an open D string.
Exercise II: Counting Aloud with a Steady Beat
The bow must be placed at its frog to start, and when a count of ten is reached, the bow should be at its tip. Be sure students know before they start, how many beats per bow you want them to play. Also important is the speed with which these instructions are given, when you call out the number of beats for the next bow. Give the instructions briskly, and ask for quick compliance, so students do not have too much time to analyze. Remind students to watch their string to make sure it is vibrating as widely as possible.
- Ask students to play one down-bow lasting ten beats, trying to make the string vibrate widely.
- Then reverse the exercise by starting at the tip of the bow. Ask students to play one up-bow lasting ten beats, trying to make the string vibrate widely.
Within a small amount of time, students will begin to better judge the speed at which their bow needs to travel in order for them to be at the opposite end of the bow within a particular number of beats, while maintaining a wide string vibration. Keep reminding them to move the bow at a consistent speed so that they reach the end of their bow exactly on the last number of the count. Once the majority of students have mastered this, vary the number of beats going up and down, and then slowly decrease the number of beats to only one beat down-bow and one beat up-bow.
- Ask students to play one down-bow and one up-bow each lasting nine beats, trying to make the string vibrate widely.
- Ask students to play one down-bow and one up-bow each lasting two beats, trying to make the string vibrate widely.
- Ask students to play one down-bow and one up-bow each lasting eight beats, trying to make the string vibrate widely.
- Ask students to play one down-bow and one up-bow each lasting six beats, trying to make the string vibrate widely
- Ask students to play one down-bow and one up-bow each lasting one beat, trying to make the string vibrate widely.
Mixing it up is fun for students. For example, have them play up-bow for ten beats, and down-bow on one beat.
I hope you will find these exercises helpful. I look forward to your feedback.
 Simon Fischer, Basics: 300 Exercises and Practice Routines for the Violin, ed. Hinrichsen (London: Peters Edition Limited, 1997), 48.
 Fischer, Basics, 18-20, 48-53.
 Ivan Galamian, Principles of Violin Playing and Teaching, 3rd ed. (Englewood Cliffs: Prentice-Hall, 1985).
 Galamian, 103.
 Carl Flesch, The Art of Violin Playing: Book I, ed. Frederick Herman Martens (New York: NY, Carl Fischer, 1923) (revised 1939), 76.
 Fischer, Basics, 19.
 Galamian, 103.
 Gaging is not common in American usage. Gauging is better known.
 Galamian, 103.
 Flesch, The Art,76.