Figure Out Any Song by Ear: Start With the Bass Line
To work out a song's chords by ear, find the key, use a media player's equaliser to cut the highs so the bass line stands out, name each bass note, then use the key's diatonic chords (I, IV, V major; ii, iii, vi minor; vii diminished) to turn each bass note into a chord and check it on your instrument.
Key points
- The bass usually plays the root of each chord, so the bass line reveals the chords.
- Find the key by singing the song's most catchy note into a tuner app; it is usually the root or the fifth.
- In any major key, I, IV and V are major, ii, iii and vi are minor, and vii is diminished.
- Cut high frequencies (around 500 Hz upwards) in a media player's EQ to hear the bass clearly.
- She Will Be Loved is in Eb major: verse C minor to Bb, chorus Eb, Bb, C minor, Ab.
This lesson from Jason Zac at Nathaniel School of Music shows a practical way to work out the chords of a song using your ears, a little free technology and basic diatonic chord theory. It suits pianists, guitarists and bass players who know their major scales and want to stop searching online for chord charts. The example song is She Will Be Loved by Maroon 5.
Why start with the bass line?
The bass is the foundation of the harmony in a band. Bass instruments play single notes, and those notes are usually the root of each chord. If you can hear the bass note, you can work out the chord. When the bass plays a note other than the root (an inversion), it has a distinct sound your ear will notice.
What you need
- A media player with an equaliser, such as iTunes, VLC, Winamp or Windows Media Player. YouTube does not let you cut or boost frequencies, so it is less useful here.
- A free tuner app (Jason uses InsTuner) to show which note you are singing. There is no need to spend money.
- A notebook to write down keys, sections and bass notes.
Step 1: Listen and plan
Listen to the whole song first. Study each section, note the lyrics and sing along. Start with songs that stay in one key so the theory side stays simple.
Step 2: Find the key
Sing the note that feels most attractive and catchy across the song. It is usually the root of the key, or sometimes the fifth. Hum it into the tuner app to see its name. If you cannot sing it, find it by trial and error on a piano or guitar. For She Will Be Loved, that note is Eb, so the song is in Eb major (three flats: Bb, Eb, Ab).
Step 3: Write out the diatonic chords
In any major key the chords follow the same pattern:
- Major: I, IV and V
- Minor: ii, iii and vi
- Diminished: vii (rare in pop, but possible)
In G major that gives G, C and D major; A minor, B minor and E minor; and F# diminished. In Eb major it gives Eb, Ab and Bb major; F minor, G minor and C minor; and D diminished.
Step 4: Use EQ to bring out the bass
Equalisation is simply a volume control for chosen frequencies. Human hearing runs roughly from 20 to 20,000 Hz, and the bass lives mostly below 100 to 200 Hz. You can boost the lows or, just as effectively, cut the highs. Jason cuts everything from about 500 Hz upwards, also cuts the very lowest band at 32 Hz, and keeps the 64 Hz and 125 Hz bands strong. Sometimes the bass sits nearer 250 Hz, so experiment. The song will sound dull and the vocals will fade, but the bass will be much clearer.
Step 5: Sing and name the bass notes
Play the EQ'd song and sing the main bass note of each chord change. Ignore the decorative notes the bassist plays; you only want the root of each change. Check each note with the tuner or your instrument. In the verse of the example, the bass moves between C and Bb.
Step 6: Turn bass notes into chords
Match each bass note to its scale degree. In Eb major, C is the sixth degree, so it becomes C minor; Bb is the fifth, so it stays Bb major. The verse is therefore C minor to Bb. The chorus bass runs Eb, Bb, C and Ab, giving Eb, Bb, C minor, Ab (I, V, vi, IV). F minor, G minor and D diminished do not appear in these sections.
Step 7: Check on your instrument
This method is not a guaranteed shortcut, so always play the chords along with the recording on a chord instrument such as piano or guitar. Checking trains your ear and shows you how the song is built. Sometimes a wrong chord still sounds good, which can become a fun reharmonisation.
How to practise
Repeat the process on several single-key pop songs, writing everything in your notebook. With practice you can work out a pop song's chords almost as fast as it plays.
Questions about this lesson
How do I find the key of a song by ear?
Sing the note that feels most central and catchy throughout the song and check it with a tuner app or your instrument. That note is usually the root of the key, or sometimes the fifth.
What EQ settings help me hear the bass line?
Cut everything from about 500 Hz upwards and keep the 64 Hz and 125 Hz bands strong, with the very lowest 32 Hz band reduced. The bass sometimes sits nearer 250 Hz, so adjust until it is clearest.
How do I know if a bass note is a major or minor chord?
Work out the note's scale degree in the song's key. Degrees 1, 4 and 5 give major chords, 2, 3 and 6 give minor chords, and 7 gives a diminished chord.
What are the chords of She Will Be Loved?
In this lesson the song is in Eb major, with the verse moving between C minor and Bb, and the chorus using Eb, Bb, C minor and Ab.
Practise it
- Circle of FifthsExplore the Circle of Fifths through keys, scales, chords and intervals.
- Note ForgePractise notes and intervals, use familiar musical references, and explore keys and chords.
- All free music apps40 practice tools for harmony, rhythm, ear training and more.
Related lessons
- How to Practice Piano Chords the Right Way (Theory, Technique and Ear)Pick one note, find every chord that contains it, and play each chord in an inversion that keeps that note on top with your right-hand pinky, the chord's root in the left hand, while you sing the top note and then the bass. This trains your theory, technique and ear together.
- Laufey's From the Start: An Intervallic Breakdown of Its Richer ChordsIn Laufey's From the Start (key of Db major), each melody note can be heard three ways: as a scale degree of the root Db, as an interval from neighbouring notes, and as a chord tone, so the same F is the 3rd of Db, the 9th of Ebm9 and the 13th of Ab13.
- How Music Theory and Ear Training Are Really the Same ThingMusic theory and ear training are best learned together: ear training is your instinct for recognising what you hear, music theory is the prepared knowledge that explains it, and transcription is the practice that joins the two.
- How to Figure Out Any Song's Chords by Ear: 5 Ear Training StrategiesTo figure out a song's chords by ear, first mark where the chords change and find the song's scale, then narrow down each chord using the bass note, cadences, the melody's landing notes, the chord's quality, and its sense of tension or rest.