Modal Interchange: Borrowed Chords and How Composers Use Them

What Is Modal Interchange?

Modal interchange is taking a chord from a different key or mode — usually a parallel one — and using it in the key you are in. The chord is said to be borrowed, which is why the technique is also called using borrowed chords, and why the two terms mean the same thing.

One term needs pinning down first, because it is the source of most confusion around this topic. In English, the parallel key or mode is the one built on the same tonic: C minor is the parallel minor of C major, and C Dorian, C Lydian or C Mixolydian are its parallel modes. This is not the relative key, which shares the key signature but has a different tonic — A minor is the relative minor of C major. (Several languages use the word "parallel" for the relative key instead, which is where the mix-up usually starts.) Modal interchange borrows from the parallel side: same root, different scale.

The idea rests on a simple observation: different modes have different chords. C major has a major IV (F) and a major V (G); C minor has a minor iv (Fm) and, unless you raise the leading tone, a minor v. C Mixolydian has a major ♭VII (B♭) and a minor v; C Lydian has a major II (D). Line up all the parallel modes on C and you have a palette of chords that are not diatonic to C major but do belong to some scale on C. Modal interchange is picking from that palette.

What distinguishes this from modulation is that the key does not change. If you use an A♭ major chord in C major, C is still home — the most restful pitch, the place the music wants to return to. Modulating to A♭ major would mean establishing A♭ as the new home. Borrowed chords are visitors; a modulation is a move.

Why Borrowed Chords Make Sense

A borrowed chord surprises the listener, but not with a random chord. Because it comes from a parallel mode, its root sits on the same scale degree as the chord it replaces, so it occupies the same place in the key even though its colour has changed. Often the function survives too: a minor iv is still a IV chord with subdominant function, and it still leads into a cadence exactly as the major IV would. With other borrowed chords the function shifts along with the colour — ♭VII does not carry the dominant pull of vii°, ♭VI leans toward the subdominant rather than standing in for the tonic-like vi, and a Lydian II can behave as a secondary dominant. Either way the chord still makes sense measured against the tonic, and the scale it came from still makes sense as a version of the home scale. That is why borrowed-chord progressions feel logical even when they contain notes from outside the key.

The effect also depends on timing. A borrowed chord only reads as borrowed once the key has been established — typically by a cadence, or by enough diatonic chords in a row that the tonic is unmistakable. At that point the listener expects the diatonic chord on each degree, so the altered note in the borrowed chord is heard as a change of colour on a chord they already know, not as a change of key. Keep the borrowed chord brief and return to diatonic harmony afterwards; if the borrowed chords start to outnumber the diatonic ones, the ear begins to hear the parallel mode as the new home instead.

One practical piece of advice applies to all of this: it matters less which mode a borrowed chord technically comes from, or how it functions on paper, than how it sounds and feels to you. The theory tells you where to look; your ear decides what to keep.

The Most Common Borrowed Chords

The minor iv. By some distance the most common modal-interchange chord: the iv from the parallel minor placed in a major key. In C major, F minor instead of F. It very often goes straight to the tonic, and the sound is nostalgic — longing, bittersweet, a little wistful. Our chord progressions guide shows how a single altered note (A to A♭) does the work, and how you can split the bar so that F sounds first and then darkens to F minor. In a "set out for adventure" theme, an inverted iv as the second chord immediately says that things are colourful, a little mysterious, not entirely safe.

♭VI and ♭VII. The major chords on the flat sixth and flat seventh, borrowed from minor. Both are bold and confident — a major chord from outside the key sounds more major than the diatonic ones, which is exactly the lift a hero theme wants. Go I to ♭VI instead of I to vi and the theme stays positive and heroic while gaining weight. The cadence ♭VI–♭VII–I (A♭–B♭–C) is triumphant and uplifting, and so familiar from game and film music that it has two nicknames: the Aeolian cadence, because its bass climbs through the lowered sixth and seventh degrees of the Aeolian mode into the tonic, and the Mario cadence, after the level-complete fanfare of Super Mario Bros. — a progression Koji Kondo did not invent but used constantly. It approaches the tonic through two major chords from outside the key and arrives without a leading tone, which is why it sounds broad and open rather than tense. Part of that openness comes from the voice leading: the three chords are usually moved in parallel, bass and upper voices climbing together in whole steps, which classical part-writing forbids and which is exactly why the arrival feels like a lift rather than a resolution.

♭III. The major chord on the flat third, also from minor, and one you will end up using more than most. It shares a common tone with the tonic (G in both C and E♭), which makes it a chromatic mediant as well as a borrowed chord, and it is bold, strong and incredibly useful. Alternating between I and ♭III has a light-hearted, swaying feel: that shared note keeps the switch smooth even though ♭III lies outside the key.

♭II. Borrowed from Phrygian, and special because it sits a half step above the tonic, so it leads back down very naturally: D♭maj7 to Cmaj7. In classical harmony the same chord in first inversion is the Neapolitan sixth: a predominant chord that stands in for ii or iv and leads to V.

iiø7. The half-diminished ii from the minor scale, used in a major key, gives a bittersweet feeling similar to the minor iv. I–♭VI–iiø7–V–I is the familiar I–vi–ii–V recoloured with borrowed chords: a major-key frame with borrowed chords inside it.

II from Lydian. Going the other way — borrowing a brighter chord into a major key — the major II from Lydian (D major in C) has enormous energy and lift. The same chord could be read as V/V; what decides it is where it goes. Followed by V, it is a secondary dominant; followed by I, IV or anything other than the dominant, the ear hears a Lydian II.

I7 from Mixolydian. A dominant seventh on the tonic gives a bluesy or jazzy flavour and tends to sound like V/IV; pair it with IV7 and the blues is unmistakable. Some borrowed chords simply end up sounding like secondary dominants — ♭VI7 almost always does — and it helps to know that in advance.

The Piano Composer Modes, modal interchange, chromatic mediants and planing, practised at the keyboard and turned into complete pieces. Explore the course

The eight chords below are the ones composers reach for most often, not a complete list. Modal interchange means borrowing from any of the other modes built on the same tonic — the parallel minor, Dorian, Phrygian, Lydian, Mixolydian, Locrian — and every chord in every one of those modes is a candidate, as a triad or as a seventh chord. Start with these eight; the rest follow the same logic.

Borrowing in Minor Keys

The traffic runs both ways. The most common borrowed chord in a minor key is the major V, which technically comes from the parallel major (or, equally, from harmonic minor): the raised leading tone gives the dominant its pull. The vii°7 from harmonic minor is the other dominant you can borrow — the chord vamp under the Pokémon Red and Blue menu theme is essentially that chord.

Borrowing the major IV into a minor key produces the Dorian sound: minor with a happy twist, still serious but brighter, which suits a fantasy world that is strange without being threatening. Flipping between parallel major and minor in either direction — a minor I appearing late in a major piece, or a major I in a minor one — is a tool for contrast and interest that should not be underestimated. And some borrowings are rare enough to be memorable: a minor vi7 — the vi chord of the parallel major, used inside a minor key — is extremely unusual, and the main theme from Breath of the Wild is one of the few well-known examples.

The possibilities are not endless, though. Some chords simply do not occur in any of the usual parallel scales — none of the seven modes, nor harmonic or melodic minor, contains a ♭II°7 or a ♭II7 — and that limit is useful. It keeps the palette small enough to actually learn.

Two Half-Minor, Half-Major Progressions

Because parallel major and minor share a root, a progression can be half one and half the other. A♭ major and E♭ major from C minor sitting next to F major and C major from C major produces a progression that is neither major nor minor, and a melody adjusted to fit it gains an unpredictable, spacey quality — you do not quite know where it is going.

A specific version worth knowing is the backdoor ii–V. In G major, Cm7–F7–Gmaj7 sounds like a iv and a ♭VII borrowed from G minor resolving home — which is what it is in practical terms. But Cm7–F7 is also a ii–V in B♭ major, so the phrase sets up one key and lands in another. Same chords, two readings, and the ear enjoys both.

Borrowed Chords in Film, Game and Anime Music

Lift and grandness. A flying theme that is mostly safe, diatonic and happy — I–vi–IV–V–I — can pull chords from other modes at a few chosen moments to give the melody extra pull and power. Two major chords a third apart that no single key contains, F and A♭ in C, are the classic case: the major chords from outside the key feel more major.

Brightness from the flat side. In A major, a run of G, F and C major chords — ♭VII, ♭VI and ♭III, all borrowed from A minor — reads as very bright, because each one is a major chord arriving from outside. Two of them, F and C, also stand in a chromatic-mediant relationship to A, a third away from the tonic; the G does not, but the effect is the same: major chords from beyond the key, used for lift.

Ration it, and let the bass choose. A progression needs surprisingly few borrowed chords to sound coloured: a diatonic skeleton with one or two non-diatonic chords — a ♭VII, say, and a secondary dominant — already reads as spiced, and beyond that the progression starts to taste of nothing but spice. When several borrowed chords would fit a bar, the bass line is a good referee: choose the one that lets the bass keep moving by step into the next chord, especially on the way into a cadence. A period-form theme in A major that draws on II, ♭VII, ♭VI7, iv and v is not chromatic for its own sake; each chord is where it is because the bass arrives on the beat.

A borrowed cadence. Placing the borrowed chords at the cadence, rather than in the middle of the phrase, is the most economical use of them, because cadences are where the listener's attention is. Ending an answer phrase with iv, then ♭VI, then I — or I augmented for a little extra twist — turns a plain theme into one with a recognizable ending, and that ending becomes an anchor the listener waits for the next time round.

Stability and instability. In sonata-style writing, staying diatonic and close to home reads as stable; moving away from the home key with borrowed chords reads as unstable. That is a structural tool: use borrowed chords in the section that is supposed to feel unsettled, and keep the return home clean.

Knowing when not to. A Viking theme that is meant to feel clean and solid avoids modal interchange along with every other kind of chromaticism, and finds its contrast by living on the V chord for a while instead. In a mode-mixing passage that goes too far, a harpist may not be able to keep up with the retuning — one practical reason to ration the chromaticism, or to write for two harps.

The Legend of Otoe: Levels 2 & 3 Modes and borrowed chords in three hands-on workshops, then altered dominants and tritone substitution — the harmony of anime and JRPG music. Explore the course

Borrowed Chords as a Bridge Between Keys

Borrowed chords also solve a modulation problem. Smooth modulations usually rely on a pivot chord that both keys share — but distant keys often share nothing. The workaround is to mix major and minor freely on either side of the modulation: F major and F minor are both IV chords in C, with different colours but the same function, so if the two keys have no pivot chords in common, ask whether they would if you used the opposite mode. The Neapolitan does something similar: with ♭II in the toolkit, any major chord can be treated as the ♭II of another key, so from C major the chords C, F and G can lead to B, E and F♯ respectively. Our guide to the circle of fifths shows how far those jumps are.

How to Use Modal Interchange in Your Own Music

1. Write the diatonic version first. A clear I–IV–V–I or I–vi–IV–V gives the borrowed chord something to contrast with.
2. Start with iv. Change IV to iv and listen. If it is too much, split the bar: IV first, then iv.
3. Try the major chords from minor. ♭VI, ♭VII, ♭III. Use them where the theme wants lift, and try ♭VI–♭VII–I as a cadence.
4. Notice the function. Some borrowed chords keep it (iv is still a subdominant), others shift it (II may turn into V/V). Decide which you want before you commit.
5. Ration it. One or two borrowed chords in a progression read as colour. A progression made entirely of them reads as a different key.
6. Trust your ear over the label. Which mode a chord came from matters less than how it feels in context.

For the wider context, see our complete guide to chord progressions for composers, and for the borrowed-chord modifications of the anime progression, our Royal Road guide.