If you see no sharps or flats between the clef and the time signature, the song is in the key of C.
1 sharp: G; 1 flat: F 2 sharps: D; 2 flats: B flat 3 sharps: A; 3 flats: E flat 4 sharps: E; 4 flats: A flat 5 sharps: B; 5 flats: D flat 6 sharps: F sharp; 6 flats: G flat
For example, the key signature for G has 1 sharp — F sharp. One half-step up from F sharp is G. With flats, read the flats from left to right and look at the second to last one. For example, the key signature for B flat has 2 flats, so the first flat, B flat, is also the second to last.
For example, suppose you have a key signature with 1 sharp, which you know is G Major. If you look on the circle of fifths, you’ll see a lower-case “e” in the same position on the circle as G Major. That tells you that E minor is the relative minor of G Major. Each key is one-fifth apart if you go around the circle clockwise, which is why it’s called the “circle of fifths. " If you go counter-clockwise, the keys are only a fourth apart, so sometimes you’ll also hear it referred to as the “circle of fourths,” but both of these terms refer to the same thing.
The major and minor scales use the same notes, but they start in a different place. If you can see pieces of these scales in the song, you’ll be able to identify the scale. You can also look at the first and last notes of the song. Typically, one or both of them will be the same note as the name of the key. So, for example, if the song ends on G, you might determine that the song is in G major and not E minor.
For example, “Fireflies,” by Owl City, is in D sharp/E flat Major, but it starts and ends with a G chord. And while originally an electronic song, it’s a simple and pretty song to play on guitar. [9] X Research source If the last chord of the song makes the song feel unsettled, it probably doesn’t identify the key the song is in. However, if it brings resolution to the song, the song is probably in that key.
For example, the song “Bad Moon Rising,” by Creedence Clearwater Revival, has only 3 chords: D, A, and G. [11] X Research source The first chord is a D, and the D-A-G pattern continues through the verses, with the choruses switching up to G-D-D-A-G-D. All 3 of these chords are found in the key of D Major, and the song starts with D, so if you guessed the song is in D Major based on that information, you’d be correct. Most keys have 1 or 2 chords in common, but never more than 2. If you identify 3 or 4 chords, you can identify the key.
If you’re using a tab, you might also see Roman numerals at the top of the page that tell you the chord progression. For example, I-IV-V is a common chord progression. If the song was in D Major, the chords used would be D, G, and A — the chords already identified in “Bad Moon Rising. " Many simple pop and rock songs are 3- or 4-chord songs, which makes it relatively easy to determine what key the song is in if you have a basic understanding of the chords in each key.
As you listen, try to pinpoint the note that seems to resolve each musical phrase, the note that feels like home. This will likely be a note the music returns to many times throughout the song. This note is referred to as the “tonic note” or the “tonal center” of the song and tells you what key the song is in.
If the note doesn’t blend in or seems to clash with the song, you might not have chosen the right note. If you don’t have perfect pitch, though, it might also be the case that your humming was slightly off-key. Many pop and rock songs change key. To identify the main key the song is written in, repeat the music behind verses, as opposed to the music accompanying the bridge or even the chorus.
If you don’t have perfect pitch, you might have to noodle around a little on your instrument before you find the note that matches the one you identified. You might also have to play the recording again. Just keep at it! This kind of experience helps train your ear so notes will be easier to find by ear in the future. If you’re playing a guitar, you can play either the chord or the single note. If the chord sounds like it fits along with the song, you’ve also found the key.
Go back to your tonic note and look at how the other notes or chords in the song relate to that tonic note. This applies to the way the music of a song sounds, not the lyrics. Songwriters often juxtapose melancholy or serious lyrics with music in a bright and poppy major key (think “Semi-Charmed Life,” by Third Eye Blind, or “Hey Ya!” by Outkast, both in G Major). [17] X Research source
