Learning to determine the key of a song or piece is an important gift in the musical field. Knowing it allows you to transpose the song (change the key) to better suit your voice; as well as experimenting with songs with different sounds (an important gift for producing an interesting cover of a certain song). To determine the key of a piece, you will first need to understand some basic concepts of music theory. The piano is the simplest tool to use to explain and understand these concepts.
Steps
Part 1 of 3: Getting familiar with some basic musical terms
Step 1. Understand the meaning of tone and semitone
Both are intervals or the distance between two notes. They constitute the "steps" of the musical scales.
- A scale is a group of notes organized in ascending order that includes an octave, a set of eight notes. For example, the major scale in the key of C is Do Re Mi Fa Sol La Si Do; while the base note of the scale is called "tonic".
- If you think of the ladder indicated above as a real ladder, each semitone represents a rung above the previous one. Therefore, the distance between B and C is one semitone as there are no other "pegs" between them (on a piano, the B and C keys are the white ones directly next to each other, with no black keys in the middle). The distance between C and D, on the other hand, is one tone, since there is an additional "peg" between those two notes in the scale (ie the black key on the piano, representing C # or D ♭).
- In the C major scale, the only semitones are located between B and C and between E and F. All other intervals are made up of whole tones because the C major scale does not include accidentals - sharps (#) or flats (♭).
Step 2. Understand the major scales
Major scales always have the same pattern of tones (1) and semitones (½), that is: 1 - 1 - ½ - 1 - 1 - 1 - ½. Hence, the C major scale is Do Re Mi Fa Sol La Si Do.
You can create any other major scale by changing the starting note, the "root note" and following the interval pattern presented above
Step 3. Understand the minor scales
Minor scales are a bit more complicated than major scales and can follow several other patterns. The most common pattern for minor scales is that of the natural minor scale.
- The natural minor scale has the following tone and semitone pattern: 1 - ½ - 1 - 1 - ½ - 1 - 1.
- You can transpose this pattern (ie rewrite it in a different key) starting with a different note and counting the various "steps" that make up your scale.
Step 4. Understand musical thirds and fifths
Thirds and fifths are types of intervals (distances between notes) that are very common in music. They can be useful in determining the key of your song. Minor intervals have one semitone less than major intervals, which alters their sonority.
- A musical third is composed of the first and third of a scale. A major third has two tones between notes, while a minor third has three semitones between them.
- A musical fifth is made up of the first and fifth notes of a scale. A "perfect" fifth has seven semitones.
- If you know Leonard Cohen's song "Hallelujah", you will have heard of the musical intervals in this verse: "It goes like this, the fourth, the fifth, the minor fall, the major lift, the baffled king composing 'Hallelujah'" (it works like this, the fourth, the fifth, the minor fall, the major passage, the perplexed king composes 'Hallelujah'). In many pop songs (often written in C major) a very used chord progression is the transition from "fourth" to "fifth" which creates a "cheerful" sound. In the song above, the words "minor fall" are accompanied by a minor chord, while the words "major lift" are accompanied by a major chord.
Step 5. Understand Major Chords
A basic chord contains three notes, which make up a triad, organized into thirds (see Step 4). These chords are usually based on a scale, such as C major. Major chords have a two-tone interval between the first and second notes of the triad. A major chord contains a major third and a perfect fifth. The first note of a chord is called the root of the chord.
For example, to form a chord based on the C major scale, you could start with the note C, the "root", and use it as the basis of your chord. Then move to the third of the scale (4 semitones up), the E, and then even higher on the fifth (3 more semitones up to G). The major triad of the C major chord is therefore C - E - Sol
Step 6. Understand the minor chords
The type of most chords is determined by the third, the middle note of the triad. Minor chords have three semitones between the first and second notes of the triad, as opposed to the four semitones (or two tones) of major chords. A minor chord contains a minor third and a perfect fifth.
For example, if you move your fingers one tone from the root of the C major chord, you will play this chord: D - F - A. This is the D minor chord, because the interval between the first and the second note of the chord (D and F) is 3 semitones
Step 7. Understand augmented and diminished chords
These chords are not as common as major or minor ones, but are sometimes used to create particular effects. Due to their alteration of traditional triads, they create a melancholy, nefarious or ghostly effect in the melody.
- A diminished chord contains a minor third and a diminished fifth (lowered by a semitone). For example, a diminished chord of C will be: Do - Mi ♭ - G ♭.
- An augmented chord, on the other hand, contains a major third and an augmented fifth (augmented by a semitone). For example, a C augmented chord will be: Do - E - G #.
Part 2 of 3: Reading the Score to Find the Key
Step 1. Find the stair reinforcement
If you have the printed score, you can find out the key of a song by looking at its armor. It is the set of symbols located between the clef (violin or bass) and the tempo (the numbers indicated in the form of fractions).
- You will see # (sharp) or ♭ (flat)
- If neither # nor ♭ are listed, the song is in C major or A minor.
Step 2. Read the flats
For scripts that use flats, the scale sign is the one next to the last flat reading from left to right (the second starting from the right).
- If a song has flats marked on B ♭, E ♭ and A ♭, the E ♭ will be the one next to the last sign of the flat and consequently the key of the musical piece will be E flat.
- If there is only one flat, the song is in D minor or F major.
Step 3. Read the sharps
For scale accidents that use sharps, the scale signature is a semitone above the last sign of the sharp.
When a song has sharps marked on F # and C #, the note after C # is D, so the piece of music is in the D scale
Step 4. Consult the chord diagrams
If you play guitar, you will likely refer to chord diagrams when learning new pieces. Many songs begin and end with the chord following the armature. If a piece of music ends in a D chord, it will likely be in the D scale.
The three basic chords in the C major scale are C major (C - E - G), F major (F - A - Do) and G major (G - B - D). They form the basis of many pop songs
Step 5. Memorize some scales
Learning to quickly recognize some of the most common scales of the genre of music you play will help you understand the key of the song. The notes of the chord will all be part of the scale.
- For example, the F major chord is F - A - C and all these notes are part of the C major scale, so the F major chord will also be part of the same scale.
- The A major chord (A - C # - E) is not part of the C scale, because the C major scale has no sharp.
Step 6. Make a reasoned estimate
Most pop music tends to use a few common scales, being the easiest to play on the guitar or piano, often the accompanying instruments.
- The C scale is by far the most common scale for pop songs.
- Search within the melody for the notes that make up the C major scale: Do - D - E - F - G - A - Si - Do. Do the notes of the melody agree with those of the scale? If the answer is yes, then the song is probably on the C scale.
Step 7. Pay attention to variations
Remember that melodies sometimes have variations, i.e. notes marked with the symbols ♭ or #, even if they are not shown in the armature.
The variations do not change the overall tonality of the piece
Part 3 of 3: Finding the Ear Key
Step 1. Find the root
The root, which is the first note of the scale, will simply sound good at any point in the song. With a piano, or with your voice, play one note at a time until you find the "right" one with the song.
Step 2. Try the tonic
By playing other notes of the triad you should be able to hear if the chord sounds in tune with the song. Play the fifth above the note you think is the root. The fifth should also sound in tune for most of the song, being the second most stable note on the scale.
Plays the note one semitone lower than the root note, the seventh. You should feel some tension in the context of the song, as if this note is pulling to become the root
Step 3. Determine if the song fits on a major or minor scale
Play the top note of a major third to the root. If this note fits well into the song in general, then the melody is likely to have a major scale context. If not, try playing a minor third (3 ♭) and listen if it sounds better.
- Practice listening to the difference between a major and a minor triad, playing the following: C - E - G, major triad with C as the tonic. Then change the E to E ♭. Do - E ♭ - G. Hear the difference in sensation and tonality in general.
- You may be able to guess whether it is a major or a minor scale simply from the feel of the song, in many western songs, the minor scales sound sad or gloomy.
Step 4. Try some chords
The most common chords of a scale should also be recurring. A commonly used scale is that of G major, which always follows the pattern: G - A - B - Do - D - E - F # - G. Its chords are G major, A minor, B minor, C major, D major, E minor and F # diminished.
- Songs in the G major scale will have chords that use these notes.
- For example, Green Day's song "Time of Your Life" begins with a G major chord (G - Si - D), followed by a C major (C - E - G) chord. Both are part of the G major scale, so the whole song is in G major.
Step 5. Sing and follow the melodies
Pay attention to songs for which it is easy for you to follow and sing the melody, as opposed to those that seem to be too high or too low and are difficult for you.
Over time you will begin to realize that some keys fit easily into your vocal range, while for others you may struggle to reach all the notes. This will help you make a rough estimate of the scale even before picking up an instrument
Step 6. Practice your new skills
Make a playlist of some of your favorite songs to sing, or use the radio to determine the keys of the songs. You may begin to notice certain patterns repeating themselves; songs in the same key should begin to sound similar to each other.
- Keep a list of the songs you've studied, categorizing them by key.
- Listen to several songs in the same scale in a row to practice hearing that particular key.
- Compare songs in different keys to see if your ear can tell the difference.
Step 7. Verify your findings
Understanding basic music theory is great if you want to write your own songs or adapt those of others to your style; however, sometimes you may just need a quick check of the scale. There are a number of websites and mobile applications that can help you find the scale of a song.
- Doing a quick search for the song name and the respective scale might lead you to a quicker solution.
- When you're just starting out in figuring out how to find tones by ear, it's a good idea to double check if you're finding the right answer.
Advice
- Listen to songs you know the key of and try to recognize the chords that follow. The more you practice and refine your "ear", the easier it will be for you to discover the key of the song.
- There is a considerable amount of potentially confusing technical music theory vocabulary in the article, but once you become familiar with scales and chords on an instrument, it will all become clearer.
