When I was in college, I was very fortunate to have workshopped and performed a truly huge array of pieces with student composers (I always have and still do love that process, hence the existence of this blog). One problem that I remember coming up very often was a composer being genuinely surprised to have learned they wrote a borderline unplayable 4-mallet part. There was no intention of writing something virtuosic, but the music would still teeter on impossible. A major contributor to this issue was a lack of understanding of interval changes in one hand.
There are a few general rules, or guidelines, to consider when dealing with this concept. If you haven’t read my post about graduated bars (and need help understanding it), I’d recommend doing that now.
- The bigger the change in interval, the harder the change. Shifting a third is harder than shifting a second, etc.
- Moving between comfortable intervals (thirds through sixths, more or less) is far easier than moving between more demanding ones, such as octaves or larger, or in some cases seconds.
- An interval shift that also involves both mallets moving adds another element of difficulty. The more action that is required, the more opportunities there are for something to go wrong.
Below are a few examples of changing intervals. Assume for this that the music demands all notes be played by one hand.
Example A: Very easy. Aside from being in comfortable intervals (4ths and 5ths) this example has only one voice changing, as well as only changing by one scale degree.
Example B: Not as easy. The intervals are comfortable, and almost the same feel for the hand, but both voices have changed. In the case of graduated bars, this will require extra work as the distance between mallets will need to shrink slightly more than usual.
Example C: Just a tad harder than Example B. While one note stays constant, the interval switch is considerably larger than the previous examples, and octaves are where things start to get uncomfortable.
Example D: Practically impossible beyond a glacially slow tempo. First off, the second interval, a major 10th, is extremely difficult, and sometimes impossible, to achieve. When doable, it necessitates an adjustment in the grip that requires much more time than the essentially instant switches possible in Example A. Additionally, both voices are changing in opposite directions, and the difference between the two intervals is enormous.