To analyze a song you love with music theory, find its key, give every chord a Roman numeral, and circle the one chord that doesn’t belong to the key. That “outside” chord, such as the C minor in Radiohead’s “Creep” or the E♭ in the coda of “Hey Jude,” is usually where the song’s emotion comes from, and it’s the device you can reuse in your own songs.
Quick answer
- Most songs rest on one chord that feels like home, usually the chord the chorus resolves to. That chord names the key: “Let It Be” is in C major, and its verse runs C–G–Am–F, or I–V–vi–IV.
- Radiohead’s “Creep” is in G major and cycles G–B–C–Cm (I–III–IV–iv). The C minor is borrowed from G minor, and on guitar the whole change from C to Cm is one note moving down one fret on the D string: E (fret 2) to E♭ (fret 1).
- The coda of “Hey Jude” loops F–E♭–B♭–F, or I–♭VII–IV–I. The E♭ comes from F Mixolydian, which gives the loop a rock feel that never quite resolves.
- In “Yesterday,” which is in F major, the chords Em7–A7 set up D minor. A7 contains C♯, which isn’t in F major, and it acts as a secondary dominant pointing to the vi chord.
- Analysis pays off when you can name one device, like “minor iv after major IV,” and use it in your own song in a different key.
Best for: guitarists and songwriters who can play open chords and the F or B barre chord, and who know the songs they love by ear or from chord charts but can’t explain why those songs hit so hard. Skip if: you already label songs in Roman numerals and can spot borrowed chords and secondary dominants on first listen.
Time cost: 10 minutes a day. Your first full analysis of a four-chord song takes one 10-minute session. Most players start hearing “outside” chords in new songs within 7–10 days. Using a borrowed device in your own writing usually starts to feel natural around days 20–30 of the plan below.
How do I find the key of a song I want to analyze?
Play along with the song and find the one chord that sounds like “home.” It’s usually the chord the chorus lands on, the chord the song ends on, and the chord that shows up most. That chord names the key. Hooktheory’s data for “Creep,” for example, shows G major as the key and I (G) as the most-used chord. If two chords compete, pick the one that sounds finished when you stop on it. You don’t need perfect pitch, just a guitar and a few passes through the song.
Practice block 1: find homeDRILL: Find home
SONG: [SONG TITLE]
CHORDS: [CHORD LIST from a chord chart or by ear]
TEMPO: Play along with the recording (or metronome at [BPM])
PLAY: Strum along; stop on each chord in turn and hold it
for 4 beats with the recording paused
REPS: Stop on every chord in the song once (4-8 stops)
SUCCESS: You're done when one chord clearly sounds "finished"
and the others sound like they want to move. Write
nothing down; say the key out loud.
What are Roman numerals in song analysis and why do they help?
Roman numerals label each chord by its position in the key rather than by its letter name. Uppercase numerals are major chords, and lowercase numerals are minor. In C major, C is I, G is V, Am is vi and F is IV, so the “Let It Be” verse reads I–V–vi–IV. Once a song is in numerals, you can compare it with any other song in any key, and you can move its progression into your own key without looking up a chord chart.
Which chords belong to a major key?
Every major key has seven diatonic chords, built only from notes in its scale: I, ii, iii, IV, V, vi and vii°. In G major those are G, Am, Bm, C, D, Em and F♯dim. In C major they are C, Dm, Em, F, G, Am and Bdim. Any chord outside that list, such as B major or C minor in the key of G, uses at least one note from outside the scale. Those outside chords are the ones worth analyzing.
Practice block 2: label the chordsDRILL: Label the chords
KEY: [KEY] (from Practice block 1)
DIATONIC: Write nothing; count up the scale on your fingers:
I ii iii IV V vi vii°
PLAY: Each chord of [SONG TITLE] for 4 beats, saying its
numeral out loud as you strum ("one... five... six...")
TEMPO: 70 BPM, 4 beats per chord
REPS: 3 passes through the progression
SUCCESS: You're done when you can say every numeral on beat 1
of the chord without pausing, and you've flagged any
chord that isn't one of the seven.
How do I spot a chord that’s outside the key?
Check each note of the chord against the key’s scale. In G major the scale is G–A–B–C–D–E–F♯. B major contains D♯, and C minor contains E♭. Neither note is in the scale, so both chords are outside the key. On guitar, the quickest check is to compare the chord with its diatonic twin: in the key of G, Bm is diatonic and B major isn’t, and C is diatonic while Cm isn’t. The note that differs between the twins is the one to focus on.
What is a borrowed chord in a song?
A borrowed chord comes from the parallel key, the minor key with the same root (or the major key, if you’re starting from minor), and is dropped into an otherwise normal progression. This is also called modal interchange. The most common example is the minor iv: in G major, that’s C minor instead of C major, as in Radiohead’s “Creep” (G–B–C–Cm). The borrowed chord keeps the song’s home but changes its color, often from hopeful to aching, with a single note.
What is a secondary dominant?
A secondary dominant is a major or dominant-seventh chord that points to a chord other than the home chord. It works as a temporary V of that chord. In “Yesterday,” which is in F major, A7 is the V of D minor (the vi chord). Its C♯ isn’t in F major, and it pulls strongly toward D. Em7 comes first, so Em7–A7–Dm forms a small ii–V–i aimed at D minor. Hooktheory labels the B major chord in “Creep” as V/vi, a secondary dominant of E minor.
What is a ♭VII chord and why does it sound like rock?
A ♭VII chord is a major chord built one whole step below the home chord. In F major it’s E♭. It’s borrowed from the Mixolydian mode, which has a flat seventh degree. The long coda of “Hey Jude” loops F–E♭–B♭–F (I–♭VII–IV–I). The ♭VII avoids the strong pull of the V chord, so the loop feels open and circular, like a comma rather than a period. That’s why ♭VII turns up so often in rock choruses and fade-outs.
Why do some songs sound so familiar the first time you hear them?
Many songs share a small group of progressions, and your ear recognizes the shape before it recognizes the song. I–V–vi–IV, which is the C–G–Am–F of the “Let It Be” verse, is the best-known example. When the progression is familiar, the parts that make a song memorable are the melody, the lyric and any outside chord. That’s why good analysis looks past the common progression to the one or two details that are different.
What is the difference between learning a song and analyzing it?
Learning a song means your hands can play it. Analyzing it means you can explain why each chord is there and reuse its devices in your own songs. Most players stop at learning. The table below compares the two approaches.
| How most people “study” songs they love | What actually builds songwriting skill |
|---|---|
| Memorize chord shapes from a tab site | Label every chord with a Roman numeral in the song’s key |
| Treat every chord as equally important | Circle the one or two chords outside the key |
| Describe the song as “sad” or “catchy” | Name the device: “minor iv after IV,” “♭VII loop,” “ii–V into vi” |
| Copy the whole progression into a new song | Take one device into a different key and a different progression |
| Read a theory explanation and move on | Play the song with and without the outside chord and hear the difference |
| Analyze on paper | Analyze with the guitar in your hands and find the one note that changes |
How do I analyze “Creep” by Radiohead with music theory?
“Creep” is in G major at about 92 BPM (per Hooktheory) and repeats four chords: G–B–C–Cm. The steps below show the full analysis: finding the key, labeling the chords, finding the outside notes, following the one note that moves, and playing it. The tab is an original exercise that follows that note, not a transcription of the recording.
Step 1: find the key and label the chords
G sounds like home, so the song is in G major. G is I. B major is III, the chord Hooktheory labels V/vi because it leans toward E minor. C is IV. C minor is iv, borrowed from G minor. Two of the four chords are outside the key, which is unusual for a pop song. Far Out Magazine describes the major III and minor iv as the song’s two “atypical” chords.
Step 2: find the outside notes
| Chord | Numeral | Notes | Outside G major? | Open or barre shape |
|---|---|---|---|---|
| G | I | G B D | No | 320003 |
| B | III (V/vi) | B D♯ F♯ | Yes, D♯ | x24442 |
| C | IV | C E G | No | x32010 |
| Cm | iv (borrowed) | C E♭ G | Yes, E♭ | x3101x |
Step 3: follow the moving note on one string
Play just one note from each chord on the B string: D (fret 3) over G, D♯ (fret 4) over B, E (fret 5) over C and E♭ (fret 4) over Cm. The line climbs a half step at a time and then drops back a half step. That rise and fall of a single note is the song’s harmonic tension, reduced to one string. You can also hear it inside the open chords: C (x32010) turns into Cm (x3101x) when the E on the D string, fret 2, moves down to fret 1.
G B C Cm
e|------------|------------|------------|------------|
B|--3---------|--4---------|--5---------|--4---------|
G|------------|------------|------------|------------|
D|------------|------------|------------|------------|
A|------------|------------|------------|------------|
E|------------|------------|------------|------------|
one note per bar, let it ring 4 beats (92 BPM)
Practice block 3: the Creep note map
DRILL: The "Creep" note map
PROGRESSION: G (320003) - B (x24442) - C (x32010) - Cm (x3101x)
TEMPO: 92 BPM, one chord per bar (4 beats)
PLAY: Pass 1: strum each chord once, let it ring
Pass 2: B-string line only: fret 3 - 4 - 5 - 4
Pass 3: strum the chords while singing the B-string line
REPS: 4 loops of each pass
SUCCESS: You're done when you can sing D - D# - E - Eb over the
chords and point to the exact fret where each outside
note (D# and Eb) lives, without looking at this page.
How do I prove what a chord is doing in a song?
Advanced analysis tests a chord instead of just labeling it. Take out the outside chord, put in its diatonic version and listen for what disappears. Then take the device into a new key and see whether it still works. Finally, look for other songs that use the same device. These three tests turn “I think the Cm is sad” into something you can check and reuse. Each one is described below and works on its own.
What is the subtraction test?
Play the progression twice at the song’s tempo: once as written and once with each outside chord replaced by its diatonic twin. In “Creep,” that means G–Bm–C–C instead of G–B–C–Cm. Describe the difference in one word. Most players say the version without the borrowed chords sounds “flat” or “safe.” Whatever word you choose is the chord’s job in the song. If you can’t hear a difference, the chord is decoration, not the song’s key device.
Practice block 4: the subtraction testDRILL: Subtraction test
SONG: [SONG TITLE] in [KEY]
ORIGINAL: [CHORD 1] - [CHORD 2] - [CHORD 3] - [CHORD 4]
DIATONIC: Same progression with each outside chord replaced by
its in-key twin (e.g. Cm -> C, B -> Bm, Eb -> C)
TEMPO: [SONG BPM] (Creep: 92, Let It Be: 74, Hey Jude: ~74)
REPS: 4 loops original, 4 loops diatonic, 4 loops original
SUCCESS: You're done when you can name the difference in ONE
word (e.g. "ache," "lift," "open") and say which
single note causes it.
What is the transplant test?
Move the device into your own progression in a different key. If the device is “minor iv after major IV,” the key of C gives you F followed by Fm. Try it after the I–V–vi–IV you already know: C–G–Am–F–Fm–C. The moving note is A dropping to A♭: G string, fret 2 to fret 1 in the first-position F (133211) and Fm (133111) barre shapes. If the ache survives the move, you’ve found a device you can use in your own writing, not just a fact about one song.
Practice block 5: transplant a deviceDRILL: Transplant a device
DEVICE: [DEVICE NAME] e.g. "minor iv after major IV"
NEW KEY: [KEY] e.g. C major
NEW PROG: [YOUR PROGRESSION] + device e.g. C - G - Am - F - Fm - C
TEMPO: [BPM] (start at 80)
PLAY: Strum 2 beats per chord; hum a melody over it
REPS: 6 loops, then 2 minutes improvising a melody that
lands on the moving note (A -> Ab in this example)
SUCCESS: You're done when your hummed melody hits the moving
note on purpose at least twice in a row.
Why do the same devices show up in different songs?
Songwriters reuse devices that work, so a single device often links songs from different decades. The I–III–IV–iv progression in “Creep” also appears in “The Air That I Breathe,” written in 1972 by Albert Hammond and Mike Hazlewood and a hit for the Hollies. Hammond and Hazlewood were given a songwriting credit on “Creep.” When you find a device, look for two more songs that use it. Grouping your analyses by device rather than by artist turns them into a toolkit you can draw on when you write.
What can I learn from analyzing “Let It Be,” “Hey Jude” and “Yesterday”?
Each of these three Beatles songs teaches one device worth reusing. “Let It Be” (C major, about 74 BPM per Hooktheory) teaches that a completely diatonic I–V–vi–IV can carry a classic when the melody and lyric do the work. The “Hey Jude” coda teaches the ♭VII loop, F–E♭–B♭–F, for endings that feel open rather than final. “Yesterday” teaches the ii–V into vi, Em7–A7–Dm in F major, for a sudden turn toward sadness.
| Song | Key | Progression | Numerals | Device to steal |
|---|---|---|---|---|
| Let It Be (verse) | C major | C–G–Am–F | I–V–vi–IV | All diatonic; the melody carries the song |
| Creep | G major | G–B–C–Cm | I–III–IV–iv | Minor iv after major IV |
| Hey Jude (coda) | F major | F–E♭–B♭–F | I–♭VII–IV–I | ♭VII loop for an open ending |
| Yesterday (opening) | F major | F–Em7–A7–Dm | I–(ii–V)/vi–vi | ii–V aimed at the vi chord |
What is a 30-day plan for analyzing songs with music theory?
This plan uses 10 minutes a day with a guitar in your hands and no written homework. Week 1 covers keys and numerals, week 2 finding outside chords, week 3 testing what chords do, and week 4 moving devices into your own songs. By day 30 you’ll have analyzed at least eight songs and written one progression that uses a device you took from a song you love. Copy the block below into your practice log.
30-DAY SONG ANALYSIS PLAN (10 minutes a day, guitar in hand)
SONGS: [SONG 1] [SONG 2] [SONG 3] [SONG 4] (songs you love)
WEEK 1 Keys and numerals (days 1-7)
Days 1-2 Practice block 1 + 2 on "Let It Be" (C-G-Am-F)
Days 3-4 Practice block 1 + 2 on [SONG 1]
Days 5-7 Practice block 1 + 2 on [SONG 2]; say the numerals
while strumming along with the recording
WEEK 2 Find the outside chord (days 8-14)
Days 8-10 Practice block 3: the "Creep" note map at 92 BPM
Days 11-12 "Hey Jude" coda F-Eb-Bb-F: find the Eb's outside note
Days 13-14 Hunt for outside chords in [SONG 3] and [SONG 4]
WEEK 3 Prove it (days 15-21)
Days 15-17 Practice block 4: subtraction test on "Creep"
Days 18-19 Subtraction test on "Yesterday" (F-Em7-A7-Dm -> F-Em7-Am-Dm)
Days 20-21 Subtraction test on your favorite outside chord
WEEK 4 Steal and write (days 22-30)
Days 22-25 Practice block 5: transplant "minor iv" into C major
Days 26-27 Transplant the bVII loop into [YOUR KEY]
Days 28-30 Write a verse + chorus using ONE stolen device;
record it on your phone
SUCCESS FOR THE MONTH: you can play your new progression to a
friend and name, in one sentence, which song you took the
device from and what it does.
Get the free Song Analysis Case Study Kit
The kit is a free printable PDF with:
- Diatonic chord charts for all 12 major keys, with Roman numerals and both open and barre shapes, so you can label a song’s chords at a glance.
- A one-page analysis template: key, numerals, outside chords, the moving note, a one-word subtraction-test result and the device name.
- Four case-study cheat sheets (“Let It Be,” “Creep,” “Hey Jude,” “Yesterday”) with fret numbers for every outside note.
- The 30-day plan as a checklist.
Why it’s faster: the scale and chord-building steps are already done for every key. You go straight from a chord chart to “which chord is outside and why,” the part that actually improves your writing.
[LEAD MAGNET FORM SHORTCODE — e.g. your email-provider form]
Upgrade: the interactive Outside Chord Finder. Enter a key and a list of chords, and it returns the Roman numerals, flags every outside chord, names the outside note and its fret on each string, and suggests a subtraction test and a transplant key. [UPGRADE LINK]
Use an AI chatbot as a song-analysis coach
Paste this prompt into any general-purpose AI chatbot. Check the chords it uses against a trusted chord chart, because chatbots sometimes get a song’s chords wrong. Prompt last reviewed September 24, 2026; it isn’t written for any particular AI model.
You are my song-analysis coach. Don't just give me answers: ask me questions first. Song: [SONG TITLE] by [ARTIST]. Chords I'm using: [CHORDS]. 1) Ask me which chord sounds like home, then confirm the key. 2) Have me say the Roman numeral for each chord; correct me. 3) Ask me which chord is outside the key and which single note makes it outside. Tell me the fret on the [STRING] string. 4) Give me a subtraction test (in-key version) to play, then ask me to describe the difference in one word. 5) Suggest one progression in [NEW KEY] that uses the same device, and one other well-known song that uses it. Tell me how confident you are about that song's chords.
Frequently asked questions about analyzing songs with music theory
Do I need to read sheet music to analyze songs?
No. You need three things: a chord chart or your ear, the seven chords of the song’s key, and Roman numerals. All of it can be done with a guitar and chord names, without any standard notation. Free lessons like musictheory.net’s Roman numeral analysis page help, but the core skill is hearing which chord is home and which chord is outside the key.
What is the easiest song to start analyzing?
Start with a four-chord, fully diatonic song such as the “Let It Be” verse: C–G–Am–F, or I–V–vi–IV in C major. With nothing outside the key, you can practice finding the key and labeling numerals first. Then move on to a song with one outside chord, like “Creep” (G–B–C–Cm), where the outside chords are easy to hear.
What does a lowercase “iv” mean in chord analysis?
A lowercase iv means a minor chord built on the fourth note of the scale. In a major key the fourth chord is normally major (IV), so a minor iv is borrowed from the parallel minor key. In G major, IV is C and iv is C minor, the chord that gives “Creep” its ache.
How do I find the chords of a song by ear?
Find the bass note first, then test a major and a minor chord on that root. Most pop songs use chords from one key, so once you know the key, try the seven diatonic chords before anything else. If none of them fits, you’ve probably found a borrowed chord or a secondary dominant. Ear-training tools such as ToneDear’s chord-progression exercises build this skill quickly.
Is it legal to use a chord progression from another song?
Common progressions like I–V–vi–IV are shared building blocks that appear in countless songs. Reusing one device is how songwriters have always learned. But combining a borrowed progression with similar melody can lead to claims. Albert Hammond and Mike Hazlewood were credited on “Creep” because of its similarity to “The Air That I Breathe.” This isn’t legal advice, so ask a music lawyer about specific cases.
What is the difference between a borrowed chord and modal interchange?
They’re the same idea under two names. Modal interchange describes the process, borrowing chords from a parallel mode or key. Borrowed chord describes the result. Common borrowed chords in major keys are the minor iv (Cm in G), the ♭VII (E♭ in F) and the ♭VI (E♭ in G). Premier Guitar’s lesson on modal interchange demonstrates the iv, ♭VII, ♭II and ♭VI in practice.
How long does it take to analyze a song?
A four-chord song takes about 10 minutes once you know the seven chords of its key. That covers finding home, labeling the numerals and circling any outside chord. Songs with key changes or many seventh chords can take 30 minutes or more. Speed comes from repetition, so analyzing one song a day for a month is faster practice than spending an hour on one song.
Sources and free tools
- Creep, Hooktheory TheoryTab: key of G major, 92 BPM, I–V/vi–IV–iv.
- Why the Hollies are credited on “Creep,” Far Out Magazine: shared I–III–IV–iv progression; credit to Albert Hammond and Mike Hazlewood.
- The Air That I Breathe, Wikipedia: background on the 1972 song by Albert Hammond and Mike Hazlewood and the Hollies’ hit version.
- Let It Be, Hooktheory TheoryTab: key of C major, about 74 BPM, verse beginning I–V–vi–IV.
- Hey Jude, Hooktheory TheoryTab: F major, coda in F Mixolydian.
- Musical Simples: Hey Jude, Ethan Hein: the I–♭VII–IV–I coda and the ♭VII explained.
- A Music Theory Analysis of “Yesterday,” Soundcheck Rock Academy: F major; opening F–Em7–A7–Dm.
- Roman Numeral Analysis: Triads, musictheory.net: free lesson on Roman numerals.
- Teoria exercises: free chord and interval ear-training drills.
- Chord progression ear training, ToneDear: train your ear to hear I–IV–V–vi movement.
- Chords in Keys, JustinGuitar: diatonic chords explained for guitarists.
- Modal interchange lesson, Premier Guitar (Nili Brosh): soloing over borrowed iv, ♭VII, ♭II and ♭VI chords.
Version notes: All links, keys and tempos were checked on September 24, 2026. Hooktheory keys and BPMs are the values shown on their TheoryTab pages on that date and may be revised by their contributors. Chord shapes assume standard tuning (E A D G B E) at A440. The AI coach prompt isn’t tied to any particular chatbot and was reviewed on September 24, 2026.
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