When you have the feeling that one note is pulling toward or away from another note, you are experiencing the feeling of tonal tension. It is a palpable phenomenon, you can feel it in your body. And the anchor note is a point of reference that organizes this phenomenon.
Surprisingly, the anchor note itself is the only place where you experience the absence of this tension. It is a kind of gravitational center for all the other notes, and so when you arrive to it, the tension disappears. And yet, despite its absence of tension, it is responsible for all the tension that you experience in other notes.
People with some musical experience often ask if the anchor note is another way of referring to ideas like the tonal center, or the tonic, or the key note, or even the root note of a chord. The reason for setting the anchor note apart is that it’s meant to express a felt quality—the experience of tension—that may or may not be present in any of these standard concepts.
When we encounter some of these other terms, like tonic, there’s potential for a bit of theoretical remove from the experience of tonal tension. For example, in the idea of a chord root, the notion of a root note may be in reference to the first note in a consecutive triadic construction of the chord. But depending on how that chord is voiced in the song, it may be a different note entirely that feels like the focal point of tonal tension.
The term tonal center comes closer to describing this experience. But even the idea of tonal center has the potential to become a theoretical idea separate from the immediate experience of tonal tension. So using a concept—the anchor— that describes this phenomenon directly also works as a tool for considering when and how other, similar concepts align with the experience.
The experience of an anchor note comes about in a song when, in one way or another, that note is being emphasized. It may be that it’s the note in the bass, or that it’s a prominent note in the melody, or perhaps that it’s landing on a regular repetition of beats in the song. For any number of reasons, your attention is being drawn to that note.
This can also come about if the anchor note is missing at exactly the moment you expect it. If a song has notes dancing around the periphery of where the anchor note should be, but it’s not there, that is also a way of emphasizing the anchor.
If the notes of a song weren’t moving in time, it would still be possible to emphasize the anchor by making it the lowest note, or the highest note, or the loudest note, or perhaps by using an instrumental timbre that draws your attention to that note.
The experience of an anchor is also influenced by stylistic conventions—what you know and expect based on other music you’ve listened to. There are some songs, for example, where two different notes may be emphasized equally, although in differing ways. So you will bring additional experience to your listening, that isn’t necessarily contained in the specific song you’re listening to. This means that sometimes, different people will hear different anchor notes in the same song.
This kind of ambiguity invites another way of refining your experience of the anchor note, by getting to know the feelings of the individual tensions that pull toward it. Because when you get to know the sound of, say, the second tension from the anchor, or the sixth, then when you hear a note in a song that feels like that particular tension, you’ll know where the anchor should be, even if it’s not sounded explicitly in the song. And it might not be where you expected it to be.
This is when you begin to get into some very exciting questions about what’s going on in a piece of music. Why do I hear the anchor note here when my idea of the song’s key, or the tonic, or the root note, or what I’m seeing in the notation tells me something different? And it’s these kinds of questions that will lead you to ask deeper questions about the theoretical concepts you’re using as well. And perhaps even to come up with a new concept that’s slightly different than that of anchor note.