How to determine the key of a melody?

It happens that a melody comes to mind and “you can’t knock it out of there with a stake” – you want to play and play, or even better, write it down so as not to forget. Or at the next band rehearsal you learn a friend’s new song, frantically picking out the chords by ear. In both cases, you are faced with the fact that you need to understand in what key to play, sing or record.

Both a schoolchild, analyzing a musical example in a solfeggio lesson, and an unfortunate accompanist, who was asked to play along with a vocalist who demands that the concert continue two tones lower, are thinking about how to determine the key of a melody.

How to determine the key of a melody: the solution

Without delving into the wilds of music theory, the algorithm for determining the key of a melody is as follows:

1. determine the tonic;
2. determine the mode;
3. tonic + mode = name of key.

He who has ears, let him hear: he will simply determine the tonality by ear!

The tonic is the most stable sounding step of the scale, a kind of main support. If you select the key by ear, then try to find a sound on which you can end the melody, put a point. This sound will be the tonic.

Unless the melody is an Indian raga or Turkish mugham, determining the mode is not that difficult. “As we hear,” we have two main modes – major and minor. Major has a light, joyful tone, minor has a dark, sad tone. Usually, even a slightly trained ear allows you to quickly identify the fret. For self-test, you can play a triad or scale of the key being determined and compare it to see if the sound is harmonious with the main melody.

Once the tonic and mode have been found, you can safely name the key. Thus, the tonic “F” and the mode “major” make up the key of F major. To find the signs at the key, just refer to the table of the correlation of signs and tonalities.

How to determine the key of a melody in a sheet music text? Reading the key signs!

If you need to determine the key of a melody in a musical text, pay attention to the signs at the key. Only two keys can have the same set of characters in the key. This rule is reflected in the circle of fourths and fifths and the table of relationships between signs and tonalities created on its basis, which we already showed you a little earlier. If, for example, “F sharp” is drawn next to the key, then there are two options – either E minor or G major. So the next step is to find the tonic. As a rule, this is the last note in the melody.

Some nuances when determining tonic:

1)    the melody can end on another stable sound (III or V stage). In this case, of the two tonal options, you need to choose the one whose tonic triad includes this stable sound;

2)    “modulation” is possible – this is the case when the melody began in one key and ended in another key. Here you need to pay attention to the new, “random” signs of alteration that appear in the melody – they will serve as a hint to the key signs of the new key. Also worth noting is the new tonic support. If this is a solfeggio assignment, the correct answer would be to write the modulation path. For example, modulation from D major to B minor.

There are also more complex cases in which the question of how to determine the key of a melody remains open. These are polytonal or atonal melodies, but this topic requires a separate discussion.

Instead of a conclusion

Learning to determine the key of a melody is not difficult. The main thing is to train your ear (to recognize stable sounds and the inclination of the fret) and memory (so as not to look at the key table every time). Regarding the latter, read the article – How to remember key signs in keys? Good luck!