VII Interval Changes
Problems related to interval changes can plague the first few years of marimba study. To prevent these physical hindrances, it is essential that from the inception of holding the mallets, the student learn to move them correctly. Since the subject is so complicated –and therefore potentially confusing without in-the-spot demonstration and correction– the following is offered only as a guideline of the most critical aspects of efficient interval control.
General considerations
1. Keep the hand and fingers relaxed up to intervals of a tenth. Security of movement is a product of coordination, not strength.
2. Tension will negate the superior interval changing capacity of this grip. If the student wants to play with tension, it is recommended that he switch to traditional grip.
3. Hand and fingers should look graceful and curved up to intervals of a tenth. A contorted or angular looking hand position is a sure sign of tension. Remember that tension is both a symptom of something wrong and a cause for further thins to go wrong. Get rid of it NOW before the muscles can familiarize themselves with the feeling.
4. The muscles controlling the outside mallet are slower to develop than those controlling the inside. One should not be concerned if several months go by with comparatively little of the outside mallet interval changing capacity being used.
Specific considerations
While bearing in mind the above general considerations, the student should memorize the content of the following particulars (memorize, not familiarize).
1. The inside mallet will spin slightly between the thumb and the first finger as the interval changes. When the interval is opening, the mallet in the right hand will spin counterclockwise; the mallet in the left hand will spin clock wise. The direction of spin will be opposite when the interval is closing. See figure 8.
2. The first finger straightens as it flips the inside mallet up and out. As the first finger straightens, it moves from its position under the mallet to a position on the side of the mallet. See figure 9.
3. When the mallets are spread to about the position of a third, the hand configuration will be identical to the basic “rest” position described in the section on holding the mallets. The inside mallet is centered under the thumb and is in a straight line with the length of the thumb. As the interval opens and the mallet spins between the first finger and thumb, the spinning motion will roll the mallet from its central position under the thumb to a position on the side of the thumb. There is now an acute angle formed by the thumb and shaft. See figure 9.
4. If the large interval position (partially described in item 3) is to be maintained for an extended period –perhaps a passage in one-handed octaves– then the position of the thumb may be “corrected” by centralizing the pad of the thumb over the shaft. However, the shaft will not form a straight line with the length of the thumb as it did in the position of a third. The thumb merely changes its point of contact with the shaft from the side of the thumb to the pad. This realignment of the thumb is usually unnecessary and should be undertaken only when extra support is needed for Neanderthal strokes. See figure 10.
5. The first finger and thumb remain in juxtaposition. The first finger should not curl under the mallet during large intervals. The thumb and first finger work together. If the thumb is very long in relationship to the first finger, the student may have to bend the second joint of the thumb to keep it opposite the first finger on large intervals.
6. As the interval opens and closes, the end of the inside mallet will inscribe an arc in the palm of the hand. See figure 11. This path that the end of the mallet travels is a slightly curved line extending from its resting place beneath the base of the thumb (thirds), to the first joint of the second finger (very large intervals).
7. If there is any tendency for the thumb and first finger to change their point of contact on the length of the shaft, the mallet is being held at an incorrect length. If the end of the shaft catches or drags on the flesh of the palm when interval changes are being made, the mallet is being held too short. In this case the student should return to a hanging rest position (section VI) and move the end of the inside mallet up, closer to the base of the thumb to lengthen the grip on the shaft. If the student feels that the end of the shaft is not obtaining support from contact with the palm, the mallet is being held too long. In this case the student should return to a hanging rest position and move the end of the mallet down, away from the base of the thumb to shorten the grip on the shaft.
8. The second finger helps to open and close the interval and is the major means of supporting the end of the shaft in the palm. Points a through d refer to the operation of the second finger.
(a) The second finger never uncurls. Joints 2 and 3 remain bent. The second finger strays very little from a 90 degree bend. The third joint of the second finger will vary from about 100 degrees (thirds) to 90 degrees (large intervals). The only joint of the second finger which ever straightens is the first joint.
(b) The second finger pushes and pulls the end of the shaft through the arc described in item 6. Most of the pushing and pulling power of the second finger comes from the first joint; that is, the connection point of the finger to hand. As the interval grows larger and the end of the shaft is pulled toward the base of the second finger, the first section of the second finger approaches a straight line with the back of the hand. See figure 12.
(c) Since the second finger is the major means of supporting the end of the mallet in the hand, it is kept in firm contact with the last inch of shaft. The second finger applies more pressure on large intervals and when extra support is needed. The pressure is released when the interval is changed.
(d) The second finger is snapped back into its position under the shaft to help close the interval.
9. Except for extreme cases, as the end of William Penn’s 4th Prelude (where an octave and a seventh is required), the thumb is never placed between the shafts. Allowing the thumb to go into this “ham-fisted” Neanderthal position completely eliminates all the fine motor control and sensitivity offered by the opposable thumb and index finger combination. It also flattens the hand position, making all inside rotary strokes more awkward. See Figure 13.
10. The outside mallet is moved principally with fingers 3 and 4. Although the first section of the second finger follows along with the outside mallet and remains in light contact, it should not be used to “push” open the outside mallet. The second finger’s main responsibility is control and strength of the inside mallet, so it should never uncurl and leave contact with the inside mallet to help the outside mallet.
11. The motion used by fingers 3 and 4 in opening the interval is similar to that of the second finger. The angle formed by the first section of the 3rd finger and the back of the hand approaches a straight line. See figure 14. Note that in the largest intervals, the tip of the 4th finger may pull away from its contact point near the center of the palm toward the base of the fourth finger. However, the back of the first section of the 4th finger does not flatten with the back of the hand like the back of the third finger.
Note that in figure 18 there is a very large interval but the 4th finger is still touching the palm and is not “overextended”.
12. The muscles which control the outside mallet may be strengthened with the following exercise:
(a) Attempt to scratch an imaginary itch in the first joint of fingers 3 and 4 with the tips of fingers 3 and 4. See figure 15.
(b) Repeat until it doesn’t itch anymore.
(c) Although this exercise can effectively strengthen the fingers (or probably harm them if done excessively), in practice, even in large intervals, the back of the first section of the 4th finger does NOT flatten with the back of the hand. Note that in figure 18, despite the very large spread of the mallets, the fourth finger is wrapped securely around the mallet shaft and it is tucked firmly into the palm, completely UNLIKE the position of the fourth finger in the “imaginary itch” exercise shown in figure 15.
13. Study the large interval position sequence shown in figures 16, 17 & 18.
Leigh Howard Stevens 