This article comes from Hayley Bauer, a musician and writer!
Some music makes the key obvious by putting it in the title. Take, for example, classical music. Classical music often has the key identified clearly in the title of the selection. Or, if you purchase a song from Musicnotes, you will often have a transposition option, and therefore you’ll know exactly what key you are playing or singing in. But how do you determine for yourself what key a song is based on? Well, it turns out there are several aspects to look at that can help you identify the key, even when it isn’t so obvious.
When you look at the key signature at the beginning of the music, you have two main options as to what the key will be. Identify the possible major key and its relative minor, both of which share the same key signature. For example, if there are three sharps in the key signature, you most likely have a piece that is either in A major, or F sharp minor. But which one is it?
Probably the most fun way to determine whether a melody is in a major or minor key is simply to play it and listen! Many musicians and music students have a keen ear to be able to tell by sound whether a melody is major or minor. As you’re listening, you might also get a sense of which note is the tonic, and that will help you determine the key. In fact, if you are a music teacher, this is a great exercise for students, as it combines music theory and ear training.
But to determine the key without hearing the music, start by looking at the first and last notes of the melody. Many times, the melody will start and end on the tonic note, or a note in the tonic chord. This trick will not always work, as melodies can start and end on different degrees of the scale, but it is helpful in some cases to help you quickly identify the key.
Another aspect to look at is accidentals. Any song, major or minor, can have accidentals. But many times, melodies in a major key will fit more neatly into a key signature. With minor keys, you’ll sometimes, though not always, see the 7th degree of the scale raised. For example, in the case of F sharp minor, the 7th degree would be E, so you would look for E sharps if you suspected the song was in F sharp minor. In some cases, minor keys will also have the 6th degree of the scale raised. Take a look at the following melodies to see some differences between the first melody, which is in the key of A major, and the second melody, which is in the relative key of F sharp minor.
Sometimes, a melody will incorporate accidentals, rather than adhering to a key signature at the beginning of the piece or section. In this case, the following tips will be helpful for you.
Once again, identify the first and last notes of your melody. Keep in mind that those notes could be the tonic, or a note of the tonic chord. Remember, however, that this tip is not foolproof, as melodies can start and end on various notes of the scale.
Next, identify the accidentals in the melody. See if they make a recognizable key signature. If they form a key signature, it’s possible it will be in the major key formed by those accidentals.
If you’ve identified all the accidentals you see in the music, and they do not form a recognizable key signature, consider that you might be looking at a minor key. If you have an extra sharp, or a double sharp, keep in mind that it may be the raised 7th. The raised 7th may also be indicated by the absence of a flat. If you have a missing flat, see if it fits as the raised 7th of the key. The following examples show a melody in the keys of D major and C minor, respectively. They are written out with accidentals, rather than using a key signature. Notice that the C minor melody does not have a B flat as you might expect from the key signature for C minor. This is the raised 7th, often called the leading note.
Here are a couple more examples. See if you can figure out the key of the following melodies, and read on until the end to see if you are correct!
Finding the key is largely about identifying accidentals and figuring out what key they fit into. While analysing melodies is a starting point, you can also look at chords and harmonies to help you determine the key. Chords I, IV, and V are used frequently in a lot of music. Look at what chords are used in the song, and match what key they best fit into. Also, look at the phrases in the music, and identify the beginning and ending notes of a phrase. Examine and listen to the music as a whole.
These ideas for identifying the key of a piece are just a few tips to get you started. But artistry often goes far beyond these basics, so tonality may become much more blurred and difficult to identify in many scenarios. This is especially true in cases of modulation, where there can be a mixture of a key signature and accidentals. The examples above are designed to clearly illustrate the basics of finding a key, but you’ll find that an actual song is often much more complex and nuanced.
As far as understanding key signatures, you might be asking, what does it matter? It’s true - you can follow the notes without knowing the name of the key that you’re in. But when you know the key of your music, and what it means, you become more aware of patterns and focal points, and you have a deeper understanding of how the music works. Recognizing these elements helps with all sorts of things, like memorization, improvisation, analysis, adding your own embellishments, and learning a piece of music faster overall.
And, if you guessed E flat Major and B minor for the above examples (5 & 6), you’d be correct!
