This is harder than it sounds because attention is divided among many things (beat geometry, music, score reading, cues, imagined ensemble performance, etc.) that can cloud whether tempo is changing, and we can easily imagine a stable pulse even as the ictus begins to wander from the starting tempo. A few of the reasons for inadvertent acceleration or deceleration are:
- Gestures are too large so that the hand moves at too great a distance and feels rushed moving from one beat position to the next in order to get the ictus on time.
- Tension in the shoulder or a tight baton grip increase the sense of weight in rebounds and result in slowing down. A smaller gesture, therefore, with less distance to move can help.
A very useful exercise is to use a metronome to help identify your tendencies. Begin by setting the metronome at a moderate tempo. Find the beat pattern that feels comfortable and then begin to beat along with the metronome, matching each ictus to the click. After establishing a stable pulse with the metronome for a few beats, you may either switch off the metronome or (with some models) lower the volume. Continue to conduct for a few beats and then turn the metronome back on. If your tempo has accelerated, your ictus will occur before the metronome click; if it has slowed down, it will occur after the click. It’s helpful in this exercise to focus on just the basic beat pattern (two, three, four) and leave out the crescendos and left-hand cues and other gestures, the big dramatic release at the end of the phrase, and changes of articulation. Once you can keep a stable tempo with these elements left out, you can try adding them back one at a time. Try adding just the preparation, or a single cue, to see if any of these cause your pulse to slow or accelerate.
Another version of this exercise applies this idea to a short passage of music from a known piece. Mark the entrances and any releases before beginning, and then after setting the tempo for a few beats, turn off the metronome and conduct the passage. At the end, turn the metronome back on and see if your final tempo matches the initial one. The goal here isn’t necessarily to conduct with the metronome going the whole time but rather to learn how to set and maintain a stable tempo, especially as you move to make large or energetic gestures.