I have written before about the various musical functions of silences with the flow of a piece of music, and thus why we should respect notated rests. But I thought it worth spending a little time thinking about how the performer can do this. We spend a lot of our rehearsal time focusing on how to achieve the bits of the music that sound aloud, but tend to assume that the silent bits will look after themselves.
But the not-sound of a musical silence is not necessarily the same as all the not-sounds we emit (or, rather, don't emit) all the time when we're not singing, playing and conversing with people. They carry meanings created by and within the musical contexts they appear in that make positive contributions to the audience's experience, and thus need performing positively.
It's possible that conductors are particularly aware of this, given their peculiar line of work in which all their musical actions are silent, but only a few of them mean silence. It was working with conductors on how to direct a pause on a rest that got me thinking about this again - although it is in the singers' performance that you notice it when the conductor doesn't get it right. So many silences are performed as absences, as 'lights on but nobody home', when - considered dramatically - they mark the key moments when the narrative moves on.
Thinking about musical narrative in dramatic terms is useful for interpretive purposes, for charting the emotional shape of the song: this is what the concept of the thought point supports. But it also draws attention to the physical execution of this imaginative process, of what overt behaviours allow the silences to signify either as active or null.
In the musical context I in which was working with the conductors that triggered this post, the metaphor that emerged was 'hold the silence as if there's a butterfly you don't want to frighten away'. This elicited a very alert, delicate stillness, with the posture lifted and poised, and the eyes very present. Try it: notice not just how your hands are, but also your eyelids - the muscles are engaged, but there's no sense of force or extraneous tension.
Of course, not all silences involve butterflies. But I think it is a pretty good generalisation to say they all involve some kind of interaction. It may be an internal dialogue, but even the most narcissistic, self-involved song unfolds a narrative that reaches out to an imagined interlocutor.
Think again of actors. The silences are the bits they really get into. All that opportunity for meaningful gaze behaviour. You never see a character in a soap opera get halfway through a sentence, draw breath, and then say, 'I'm sorry I've completely forgotten what I was saying'. (Though come to think of it that might make them a bit more realistic...)
I guess the thing is that in acting, the interaction is usually much more explicit. Actors spend most of their time taking turns to speak with other actors, and they are expected to stay in character - to keep on acting - even while they are not talking. You don't get to do monologues until you are really quite senior in your craft as an actor, with enough experience of real on-stage interactions to be able to conjure up imaginary ones. Come to that, the most junior rung of the ladder, the non-speaking part, involves performing silence continually, so that seems like the first thing you have to master.
Musicians, by contrast, spend their juniority becoming conceptually invisible. Basic stagecraft is about blending in to the ensemble, within an aesthetic that encourages the performer to get out of the way of the composer's music. And, to be fair, the comments I've made above about continuity of character and narrative through the silences make a lot more sense applied to the soloist than they do to the 2nd oboe with 38 bars rest to count.
So, in practical terms, we can approach the performance of silences from two directions: the imaginative/interpretive (what is my character thinking and feeling here?) and the physical/technical (where is my gaze directed? what am I doing with my posture?). The second without the first will get you visual coherence within an ensemble, but will remain empty. The first without the second will probably get you very good results initially, but unless anchored in specific observable behaviours may prove hard to replicate at will.
Reading back that last paragraph, I seem to have described how to handle all expressive performance, not just silences. I'm starting to wonder if the question isn't actually: why do performers not always experience the silences as part of the music, when audiences always do? I'll tackle that one another day, if I'm feeling brave...