Musical Understanding Starts with Key Signatures

This post was first published on August 3, 2012. Updated on June 28, 2021.

At some point in every music student’s life comes the moment when she must learn all the key signatures. And at some point for every teacher comes the question from that same student: “Why do I have to know them?”

There are some easy reasons that we all give our students. They may need to learn them  for an exam. Or we can truthfully tell them that key signatures are one of the basic elements of musical literacy, and therefore they need to know them. When I was teaching music theory at the Curtis Institute of Music, the students understood that this was a necessary part of their musical education, and that was enough of a reason.

But these reasons rarely answer the student’s real desire to understand the value in committing the key signatures for thirty keys to memory.

So here is what I offer my students as the value to them in learning their key signatures. I hope you find this helpful, either for yourself in your musical journey, or for your students.

First, I repeat that a musician needs to have all the tools of their trade at the ready. For the same reason that we all have a music stand, a metronome and a pencil, we need to know our key signatures. Any college music program will expect key signatures to be part of a student's musical knowledge, and if a theory placement exam finds her skills insufficient, she will be placed in a remedial theory class. Yuck.

But if that’s the stick, here’s the carrot.

When you know your key signatures, the inner workings of music begin to appear. The patterns and the progressions of the notes make more sense, which make the notes easier to learn.

All the keys share the same set of note relationships. For instance, in every key the first and fifth notes of the scale are exactly the same distance from each other and work together in exactly the same way. Becoming familiar with these relationships between the notes in a key will help your music reading and your hearing. This means your sightreading will improve.

Knowledge of key signatures is necessary for an understanding of chords, both how chords are formed and how they work together to create the harmony of a piece of music. Practicing chord and arpeggio patterns is very helpful, but when you can bring musical understanding to your practice, you will reap much bigger rewards. Your sightreading will improve. So will your ability to improvise, play by ear, and read chord charts.

Have you ever heard a performance of a piece that was so convincing in its expressiveness that you couldn’t imagine a better one? And perhaps you’ve also heard a performance where something just didn’t seem quite right. Often the difference between the two performances is the performer’s understanding of musical form, of the cadences and phrase structure that are the skeleton of the piece. A strong musical interpretation always projects the underlying form of the piece; that’s one of the elements of clarity in music. And you can guess what you need to know to understand musical form: key signatures.

Learning key signatures is not very difficult. There are fifteen key signatures for fifteen major and fifteen minor keys. That’s thirty keys. Only four more than the letters in the alphabet. Without which you couldn’t have read this post…

If memorizing key signatures doesn't sound attractive, there are other options. The simplest way I know is to start paying attention to them. That may sound a little too simple to you; after all, you have to pay attention to key signatures to set the right levers or pedals at the start of a piece. 

But have you ever tried playing your piece without the correct sharps or flats, on purpose, that is? Try it and listen carefully as you play. What notes do you expect to sound different and in what way? Can you tell by listening what accidental you need to "correct" a note?

Over time this kind of critical listening exercise will help your ear learn to predict accidentals correctly in your music. This in turn makes your playing and your sightreading more accurate. Plus, along the way, those elusive key signatures may start to make sense!

Listen to my podcast episode about Minor Keys