Teaching the Known and Unknown in Music Lessons

In music lessons, we often talk as though the whole problem is simply that a student does not know enough yet. Sometimes that is true. But very often the situation is more complicated than that.

A student may know something securely and need help using it in a new context. They may be aware of a weakness and need a better way to work on it. They may have a blind spot they cannot yet hear for themselves. Or they may already know something in the body or ear, but not yet have language for it.

That is why I find it helpful to think in four boxes: what we know we know, what we know we do not know, what we do not know we do not know, and what we do not know we know. The first three were made famous by Donald Rumsfeld’s “known knowns / known unknowns / unknown unknowns” formulation, and the fourth box is often added later to describe tacit or hidden knowledge. That fourth category sits close to Michael Polanyi’s idea that we often know more than we can easily tell. In music teaching, that matters a great deal because so much learning is aural, physical, and only partly verbal.

This way of thinking sits behind much of my teaching philosophy. For related reflections, see why I teach music first, not exam first and what makes a musical life sustainable.

Know what you know

The first job of teaching is not only to spot errors. It is also to identify what is already stable.

If a student already keeps a reliable pulse, hears phrase direction naturally, remembers patterns well, or produces a warm sound instinctively, those are not small details. They are part of the student’s real musical knowledge. When we notice them clearly, we can build from them instead of teaching as though everything were missing.

This changes the atmosphere of the lesson. Students become less defensive when they feel that the lesson is naming genuine strengths, not merely searching for faults. It also helps the teacher work more precisely. A student who already hears contour may need technical help, not more explanation about shape. A student who reads accurately but listens weakly may need more singing, comparing, and imitation.

In practice, I want students to leave the lesson knowing exactly what is already working. That gives them something dependable to return to in their practice.

Know what you do not know

This second box is usually the most familiar one in teaching. A student knows, for example, that shifting is unreliable, counting breaks down in dotted rhythms, or vibrato disappears under pressure. These are important moments because awareness makes focused work possible.

But even here, teaching matters. If we stop at “this is weak,” the student may become self-conscious without becoming skilful. The better question is: can the student describe the problem closely enough to work on it?

Instead of saying “intonation is bad,” we might narrow it down to “the hand arrives late after the shift” or “the ear is not hearing the new note before the move.” Instead of “it sounds rushed,” we might ask whether the student loses the subdivision, the harmonic rhythm, or simply the courage to wait.

Known unknowns become teachable when they are made specific. They move from anxiety to method.

Do not know what you do not know

This is the most difficult category, and often the one that most needs a teacher.

A student may not realise that the bow change is creating a bump at the top of every slur. They may not hear that the harmony has changed and the phrase can no longer be shaped the same way. They may think they are playing with a steady pulse while the line continually tightens under difficulty. Because they do not yet perceive the problem, they cannot correct it alone.

This is where diagnosis, demonstration, and comparison become especially valuable. Sometimes I need to play two versions and ask what changed. Sometimes I ask the student to sing the line away from the instrument so that pitch and gesture become clearer. Sometimes a recording helps. Sometimes a question helps more than an answer: “Where does this phrase actually arrive?” or “Did the tone change because you chose it, or because the string crossed?”

The point is not to make students feel that they are missing everything. It is to widen perception. Good teaching turns an unknown unknown into a known unknown. Once the student can hear it, real learning can begin.

Do not know what you know

This fourth box is especially important in music. Students often possess more knowledge than they can explain.

A child may shape a phrase beautifully by imitation but have no vocabulary for cadence, tension, or release. A teenager may balance a chamber texture well without being able to describe why. An adult beginner may discover a freer tone before understanding the mechanics behind it. In each case, something real has been learned, but it has not yet become conscious or transferable.

This is where teaching can give language to experience. When we help students name what they just did successfully, we make tacit knowledge easier to reuse. “You prepared that shift by hearing the note first.” “That sounded calmer because you kept the subdivision alive.” “The line opened because you did not press at the beginning of the bow.”

That kind of naming matters because musical growth is not only about adding information. It is also about bringing partly hidden knowledge into awareness so that students can trust it, refine it, and call on it again.

How this changes music teaching

If we take these four states seriously, lessons become less about delivering information and more about guiding attention. This fits well with research on metacognition in music learning. Susan Hallam’s work on musicians’ practice describes how stronger learners engage in planning, monitoring, and evaluation, while Hans-Christian Jabusch argues that metacognition and self-regulated learning deserve explicit attention in musical practice, not only incidental development.

In practical terms, that means I want lessons to include questions like:

• What is already dependable here?
• What feels unclear but nameable?
• What surprised you when you listened back?
• What worked even though you could not yet explain it?

Those four questions map neatly onto the four boxes. They help students practise with more honesty and less vagueness.

They also remind the teacher not to use one method for every problem. Known knowns need reinforcement and transfer. Known unknowns need strategies. Unknown unknowns need revealing. Unknown knowns need language and reflection.

This approach can be used with beginners as easily as advanced students. With beginners, the language may stay simple: “What did you notice?” “What still feels unsure?” “What did I hear that you did not hear yet?” “What went better than you expected?” With advanced students, the same structure can support score study, interpretation, rehearsal planning, memorisation, and performance preparation.

Teaching as the art of making awareness more accurate

At its best, music teaching is not just the transfer of correct instructions. It is the gradual refinement of awareness.

We help students recognise what is secure, face what is weak without panic, notice what they previously could not perceive, and name what they already know in the ear, hand, or imagination. When that happens, practice becomes more intelligent. Confidence becomes steadier. And the lesson becomes less about being told what is wrong and more about learning how to hear, understand, and adjust.

That, to me, is one of the deepest purposes of teaching: not simply to fill a gap, but to help students know their own knowing more truthfully.

Sources and further reading

• Donald Rumsfeld’s 2002 formulation of “known knowns,” “known unknowns,” and “unknown unknowns” is discussed in his author’s note for Known and Unknown.
• Michael Polanyi’s The Tacit Dimension is a useful source for the idea that we often know more than we can easily articulate.
• Susan Hallam, “The development of metacognition in musicians: Implications for education”, connects musical expertise with planning, monitoring, and evaluation in practice.
• Hans-Christian Jabusch, “Setting the Stage for Self-Regulated Learning Instruction and Metacognition Instruction in Musical Practice”, argues that metacognitive instruction should be addressed directly in music learning.