Introduction to Keys
What a key is and how to find it
What is a Key?
A key is the group of notes and chords that a piece of music is built from. When someone says "this song is in the key of G," they mean:
- The melody uses notes from the G major scale (G, A, B, C, D, E, F#)
- The chords are built from those same notes (G, Am, Bm, C, D, Em)
- G feels like "home" — the resolution point, the resting place
Everything revolves around that home note (called the tonic or root). Tension is created by moving away from it; resolution comes from returning to it.
Finding the Key of a Song
Method 1: Look at the chords. If a song uses G, C, D, and Em, those all belong to the key of G major. The chord that feels like "home" (usually the first or last chord) confirms it.
Method 2: Listen for the home note. When the song ends or reaches a point of rest, which note or chord feels most resolved? That's likely the key.
Method 3: The first and last chord rule. Most songs start and/or end on the I chord (the key chord). Not always, but it's a reliable guess.
Method 4: Look for the V chord. The V chord (dominant) strongly pulls toward the I chord. If you see a D chord resolving to G, the key is probably G.
Major vs Minor Keys
Songs can be in a major key (bright) or minor key (dark):
- A song in C major: C chord feels like home, uses C major scale
- A song in A minor: Am chord feels like home, uses A minor scale (same notes as C major)
To tell the difference, listen to the feel. "Hotel California" uses the same notes as B major but the Am chord clearly feels like home — it's in A minor. The emotional quality and which chord resolves tell you major vs minor.
Tips
- The key tells you which scale to solo with — if the song is in G, use G major or E minor pentatonic
- Most pop songs are in major keys. Most rock and blues songs are in minor keys.
- The I, IV, and V chords are the most common in any key
- If you're unsure of the key, try humming the note that feels like "home"
Practice Exercises
- Take 5 songs you know and identify their key by looking at the chords
- Play G-C-D-G and feel how G is clearly "home"
- Play Am-F-C-G and feel how Am is "home" — same notes as C major but different key centre
- Improvise using G major pentatonic over a G-C-D progression — hear how the key guides your note choices