Referring to the beating diagrams in Figure 1 we can now discuss the manner of beating gestures. First, it is important to establish that the expression ‘preparatory upbeat’ is to be abandoned. The constant fluctuations of tempi in a work such as Le Marteau sans maître (especially no. 4) cannot accommodate any kind of preparatory beat at any point. Tempo has to be established by the arc of displacement between one beat and the next. A preparation is required at the commencement of a piece or section, but not a beat. Such a preparatory gesture requires only the lifting of the arm from the base-line in time with the main pulse unit as illustrated by the rising dotted line arrow in Figure 1. In a master class Boulez once compared it to turning the ignition key in a car. The beating diagrams emphasise the importance of arc shapes in the patterns. This provides scope for expressive nuances and intricate rhythmic detail. Consistent with the technique of any subject it is best to examine the issues in slow motion at first. It is preferable to use a music example rather than an academic exercise so that the artistic impulse is constantly nourished throughout the process. The Prelude of Wagner’s Tristan und Isolde provides excellent material (Example 1).

It is a very slow 6/8 tempo beginning with the cellos playing on the sixth subdivision of the bar. Two issues arise for consideration. Why has Wagner used a small, compound unit for such a slow piece? How does the conductor beat the slow anacrusis for such a quiet opening?

The answer to issue 1 is that Wagner wished the performers to think of the pulse as two beats to the bar, not six. If he had used a crotchet unit rather than a compound to make it a 6/4 pulse, the line would lose its essentially sustained, flowing character which the compound unit implies. In explaining issue 2 we do have to refer to the 6/4 diagram in Figure 1 for the actual shapes of the subdivided 6/8 music. The preparation point for the anacrusis is at the far right on beat 5.