{"id":2214844,"date":"2026-08-02T06:03:52","date_gmt":"2026-08-02T04:03:52","guid":{"rendered":"https:\/\/twelve-assistant.com\/music-theory-for-guitar\/scale-degrees-guitar\/"},"modified":"2026-08-02T06:03:52","modified_gmt":"2026-08-02T04:03:52","slug":"scale-degrees-guitar","status":"publish","type":"page","link":"https:\/\/twelve-assistant.com\/en\/music-theory-for-guitar\/scale-degrees-guitar\/","title":{"rendered":"Scale Degrees for Guitar: The I-IV-V System"},"content":{"rendered":"\n<div class=\"ta-theorie\">\n\n<p class=\"lead\">You&#8217;ve already encountered these odd notations on a forum or app: I-IV-V, ii-V-I, I-V-vi-IV. Roman numerals everywhere, and everyone seems to understand. Good news: it&#8217;s the simplest and most powerful system in all of music theory. You know <a href=\"\/en\/music-theory-for-guitar\/guitar-scales-explained\/\">the major scale and its formula<\/a>? Then you only need one thing: give a number to each of its notes.<\/p>\n\n\n<section class=\"direct-answer\" id=\"essentiel\">\n  <h2>The essentials in 30 seconds<\/h2>\n  <p>A <strong>scale degree<\/strong> is the number of a note inside a scale. In a major scale of 7 notes, each note receives a Roman numeral from I to VII: in C major, C is degree I, F is degree IV and G is degree V. We use Roman numerals because the relationships between degrees stay identical in all keys: a I-IV-V progression sounds the same whether played C-F-G or D-G-A. Thinking in degrees rather than chord names allows you to transpose any progression by only changing the starting key.<\/p>\n<\/section>\n\n<nav class=\"toc\">\n  <h2>What we&#8217;ll cover<\/h2>\n  <ul>\n    <li><a href=\"#degre\">1. What is a degree: a number for each scale note<\/a><\/li>\n    <li><a href=\"#romains\">2. Roman numerals and degree quality<\/a><\/li>\n    <li><a href=\"#fonctions\">3. Why I-IV-V works in all keys<\/a><\/li>\n    <li><a href=\"#transposer\">4. Transpose a progression without relearning anything<\/a><\/li>\n    <li><a href=\"#reperer\">5. Spot degrees in your songs<\/a><\/li>\n    <li><a href=\"#faq\">Frequently asked questions<\/a><\/li>\n    <li><a href=\"#recap\">Summary<\/a><\/li>\n  <\/ul>\n<\/nav>\n\n<!-- ============ H2 : c'est quoi un degr\u00e9 ============ -->\n<section id=\"degre\">\n  <h2>1. What is a degree: a number for each scale note<\/h2>\n\n  <p>The C major scale has 7 notes: C, D, E, F, G, A, B. Give each a number, in order, and you get the 7 <strong>degrees<\/strong>: C equals I, D equals II, E equals III, F equals IV, G equals V, A equals VI, B equals VII. (They&#8217;re read &#8220;one,&#8221; &#8220;two,&#8221; &#8220;three&#8221;&#8230; V is read &#8220;five,&#8221; not &#8220;vee.&#8221;)<\/p>\n\n  <p>Why Roman numerals and not regular numbers? To never confuse them with the fret numbers, finger numbers, or string numbers already filling your tabs. When you see a Roman numeral, you know it&#8217;s talking about the scale.<\/p>\n\n  <p>And here&#8217;s the key point: a degree describes <strong>a role, not a fixed note<\/strong>. Degree I is C in C major, but G in G major. The number says &#8220;what place in the scale,&#8221; not &#8220;what absolute note.&#8221; This abstraction is what will unlock everything.<\/p>\n\n  <div class=\"ta-card ta-widget\" data-ta-widget=\"degres-gamme\">\n    <div class=\"controls\">\n      <div class=\"ta-toggle-group\" data-role=\"mode\">\n        <button type=\"button\" data-val=\"pos\" class=\"on\">Positions (I to VII)<\/button>\n        <button type=\"button\" data-val=\"qual\">Chord qualities<\/button>\n      <\/div>\n    <\/div>\n    <div class=\"deg-row\" data-role=\"row\"><\/div>\n    <div class=\"readout\" data-role=\"readout\">Click a badge: in positions mode, it plays the degree note. In qualities mode, it plays the chord built on it.<\/div>\n    <p class=\"svg-caption\">The 7 degrees of C major. The black badge marks degree I, the tonic.<\/p>\n  <\/div>\n<\/section>\n\n<!-- ============ H2 : chiffres romains et qualit\u00e9s ============ -->\n<section id=\"romains\">\n  <h2>2. Roman numerals and degree quality<\/h2>\n\n  <h3>Major and minor degrees in the major scale<\/h3>\n\n  <p>On each degree of a scale, you can build a chord (we&#8217;ll see how in the next article). And in a major scale, the quality of these chords is <strong>automatic<\/strong>: I, IV and V give major chords; ii, iii and vi give minor chords; and vii\u00b0 gives a diminished chord, the only special one of the bunch (it contains the tritone, the unstable interval from <a href=\"\/en\/music-theory-for-guitar\/music-intervals-guitar\/\">the article on intervals<\/a>).<\/p>\n\n  <h3>Reading I, ii, iii, IV, V, vi, vii\u00b0<\/h3>\n\n  <p>In the most common convention, case indicates quality: <strong>uppercase for a major chord<\/strong> (I, IV, V), <strong>lowercase for a minor chord<\/strong> (ii, iii, vi), and the little circle for diminished (vii\u00b0). A Roman numeral thus condenses two pieces of information at once: &#8220;vi&#8221; tells you &#8220;sixth degree&#8221; AND &#8220;minor chord.&#8221; It&#8217;s a compressed word, and it works in any scale.<\/p>\n\n  <div class=\"ta-card ta-widget\" data-ta-widget=\"table-degres\">\n    <table class=\"ta-intervals\" aria-describedby=\"d2d\">\n      <caption id=\"d2d\" style=\"caption-side:bottom;font-size:.85rem;color:var(--xiia-600);padding-top:.5rem;\">\n        The 7 degrees of the major scale, with the example of C major. Click a row to hear the chord.\n      <\/caption>\n      <thead>\n        <tr><th scope=\"col\">Degree<\/th><th scope=\"col\">Note in C major<\/th><th scope=\"col\">Chord quality<\/th><th scope=\"col\">Function<\/th><\/tr>\n      <\/thead>\n      <tbody>\n        <tr data-deg=\"0\"><td>I<\/td><td>C<\/td><td>Major<\/td><td>Tonic (rest)<\/td><\/tr>\n        <tr data-deg=\"1\"><td>ii<\/td><td>D<\/td><td>Minor<\/td><td>Secondary<\/td><\/tr>\n        <tr data-deg=\"2\"><td>iii<\/td><td>E<\/td><td>Minor<\/td><td>Secondary<\/td><\/tr>\n        <tr data-deg=\"3\"><td>IV<\/td><td>F<\/td><td>Major<\/td><td>Subdominant (movement)<\/td><\/tr>\n        <tr data-deg=\"4\"><td>V<\/td><td>G<\/td><td>Major<\/td><td>Dominant (tension)<\/td><\/tr>\n        <tr data-deg=\"5\"><td>vi<\/td><td>A<\/td><td>Minor<\/td><td>Secondary<\/td><\/tr>\n        <tr data-deg=\"6\"><td>vii\u00b0<\/td><td>B<\/td><td>Diminished<\/td><td>Secondary (tension)<\/td><\/tr>\n      <\/tbody>\n    <\/table>\n    <div class=\"readout\" data-role=\"readout\">I, IV, V: the three primary degrees. The others color and nuance. vii\u00b0 is the only diminished.<\/div>\n  <\/div>\n\n  <p>But why these qualities? The demonstration live: click a degree and watch the chord build <strong>on the scale ladder<\/strong>. The root lands, the fifth too&#8230; and for the third, you have no choice: only one of the two possible positions exists in the scale. It&#8217;s the available note that decides whether the chord is major or minor.<\/p>\n\n    <div class=\"ta-card ta-widget\" data-ta-widget=\"construction-degres\">\n      <div class=\"controls\" style=\"justify-content:center;\" data-role=\"degs\"><\/div>\n      <svg viewBox=\"0 0 860 250\" role=\"img\" aria-labelledby=\"d6t\" aria-describedby=\"d6d\">\n        <title id=\"d6t\">Building degree chords on the scale ladder<\/title>\n        <desc id=\"d6d\">The C major scale spread over two octaves with real semitone distances. Clicking a degree makes its chord&#8217;s three notes appear with their colored intervals: the root in a black square, the third in red, the fifth in green. The third position absent from the scale appears as a crossed-out ghost: the available note imposes the major or minor quality of the chord.<\/desc>\n        <g data-role=\"stage\"><\/g>\n      <\/svg>\n      <div class=\"controls\" style=\"justify-content:center;margin-top:.4rem;\">\n        <button type=\"button\" class=\"ta-btn\" data-role=\"playall\">\u25b6 All 7 chords in sequence<\/button>\n      <\/div>\n      <div class=\"readout\" data-role=\"readout\">Click a degree: its chord builds before your eyes, with both interval AND note.<\/div>\n      <p class=\"svg-caption\">The code for the whole series: root in black square (R), third in red (b3 or M3), fifth in green (P5, or b5 for vii\u00b0). The crossed-out ghost is the third that doesn&#8217;t exist in the scale: that&#8217;s why you don&#8217;t choose the quality, the scale chooses for you.<\/p>\n    <\/div>\n\n    <p>Not all degrees carry the same weight. <strong>I, IV and V are the primary degrees<\/strong>: with them alone, you accompany hundreds of songs. The <strong>secondary degrees<\/strong> (ii, iii, vi and vii\u00b0) enrich, color, sometimes replace a primary. The vi minor, for example, brings that bittersweet color you hear in tons of ballads.<\/p>\n<\/section>\n\n<!-- ============ H2 : fonctions et I-IV-V ============ -->\n<section id=\"fonctions\">\n  <h2>3. Why I-IV-V works in all keys<\/h2>\n\n  <p>Beyond their number, the three pillars each have a role, a <strong>function<\/strong>. Degree I is called the <strong>tonic<\/strong>: it&#8217;s home, rest, the note that gives its name to the scale (the &#8220;starting note&#8221; from the previous article now has its real name). Degree IV, the <strong>subdominant<\/strong>, takes you away from home: it moves. Degree V, the <strong>dominant<\/strong>, creates tension that pulls toward return.<\/p>\n\n  <div class=\"ta-card ta-widget\" data-ta-widget=\"fonctions\">\n    <div class=\"deg-row\">\n      <div class=\"deg-cell\">\n        <button type=\"button\" class=\"ta-sqdeg ta-sqdeg--black ta-sqdeg--fn\" style=\"--fn-color:#2EE574\" data-deg=\"I\">I<\/button>\n        <span class=\"deg-fnlabel\">TONIC<br>rest<\/span>\n      <\/div>\n      <div class=\"deg-cell\">\n        <button type=\"button\" class=\"ta-sqdeg ta-sqdeg--white ta-sqdeg--fn\" style=\"--fn-color:#2EDCE5\" data-deg=\"IV\">IV<\/button>\n        <span class=\"deg-fnlabel\">SUBDOMINANT<br>movement<\/span>\n      <\/div>\n      <div class=\"deg-cell\">\n        <button type=\"button\" class=\"ta-sqdeg ta-sqdeg--white ta-sqdeg--fn\" style=\"--fn-color:#E52E40\" data-deg=\"V\">V<\/button>\n        <span class=\"deg-fnlabel\">DOMINANT<br>tension<\/span>\n      <\/div>\n    <\/div>\n    <div class=\"controls\" style=\"justify-content:center;margin-top:1rem;\">\n      <button type=\"button\" class=\"ta-btn\" data-role=\"tour\">\u25b6 Play round trip I-IV-V-I<\/button>\n      <button type=\"button\" class=\"ta-btn ta-btn--ghost\" data-role=\"suspend\">Stay on V (tension)<\/button>\n    <\/div>\n    <div class=\"readout\" data-role=\"readout\">Each degree has a role. Click a badge to hear its chord, or play the complete round trip.<\/div>\n    <p class=\"svg-caption\">Ending on V leaves it hanging. Returning to I closes the piece. This mechanism is <a href=\"\/en\/music-theory-for-guitar\/chord-cadences-guitar\/\">cadences, the tension from V to I<\/a>.<\/p>\n  <\/div>\n\n  <p>Now, why does I-IV-V sound the same in all keys? Because the distances never change: from I to IV there are always 5 semitones (a perfect fourth), from I to V always 7 semitones (a perfect fifth), <a href=\"\/en\/music-theory-for-guitar\/music-intervals-guitar\/\">the fourth and fifth intervals between degrees<\/a>. The semitone gaps being identical regardless of starting note, the progression tells the same story: home, movement, tension, return.<\/p>\n\n  <h3>The same I-IV-V in C, in D, in E<\/h3>\n\n  <p>In C major: C, F, G. In D major: D, G, A. In E major: E, A, B. Three different outfits, one single progression. That&#8217;s why a huge part of pop, rock, folk and blues songs rest on a handful of degrees, especially I, IV, V and vi: the skeleton is universal, only the key changes.<\/p>\n\n  <h3>The leading tone: degree VII&#8217;s magnet<\/h3>\n\n  <p>One last character deserves its name: degree VII. In C major, it&#8217;s B, only one semitone below the tonic. This proximity magnetizes it: the ear absolutely wants it to rise and land on C. It&#8217;s called the <strong>leading tone<\/strong>, and it&#8217;s the &#8220;note that pulls toward the starting note&#8221; we spotted in the scale formula. Test it:<\/p>\n\n  <div class=\"ta-card ta-widget\" data-ta-widget=\"sensible\">\n    <div class=\"deg-row\">\n      <div class=\"deg-cell\">\n        <button type=\"button\" class=\"ta-sqdeg ta-sqdeg--white\" data-role=\"b7\">VII<\/button>\n        <span class=\"deg-note\">B: the leading tone<\/span>\n      <\/div>\n      <div class=\"deg-cell\" style=\"justify-content:center;\">\n        <span style=\"font-size:1.6rem;color:var(--xiia-cyan);\">\u2192<\/span>\n        <span class=\"deg-note\">1 semitone<\/span>\n      <\/div>\n      <div class=\"deg-cell\">\n        <button type=\"button\" class=\"ta-sqdeg ta-sqdeg--black\" data-role=\"b1\">I<\/button>\n        <span class=\"deg-note\">C: the tonic<\/span>\n      <\/div>\n    <\/div>\n    <div class=\"controls\" style=\"justify-content:center;margin-top:1rem;\">\n      <button type=\"button\" class=\"ta-btn\" data-role=\"stop\">\u25b6 Climb the scale and stop on the leading tone<\/button>\n      <button type=\"button\" class=\"ta-btn ta-btn--ghost\" data-role=\"resolve\" disabled>Resolve to the tonic<\/button>\n    <\/div>\n    <div class=\"readout\" data-role=\"readout\">C, D, E, F, G, A, B&#8230; and stop. You feel the lack? That&#8217;s the leading tone demanding its tonic.<\/div>\n    <p class=\"svg-caption\">Careful not to confuse: the leading tone is a note (degree VII), the dominant is a chord (on degree V). They share tension, not identity.<\/p>\n  <\/div>\n<\/section>\n\n<!-- ============ H2 : transposer ============ -->\n<section id=\"transposer\">\n  <h2>4. Transpose a progression without relearning anything<\/h2>\n\n  <p>Here&#8217;s the concrete superpower. Memorize a progression in degrees, and you know how to play it everywhere. The method takes two steps: translate the chart into Roman numerals, then replay it in the new scale. Example: you want a IV in G major? Count the 4th note of the G scale: G, A, B, C. The IV is C.<\/p>\n\n  <h3>Translate a known progression into degrees (I-V-vi-IV)<\/h3>\n\n  <div class=\"ta-card ta-widget\" data-ta-widget=\"transposeur\">\n    <div class=\"controls\">\n      <div class=\"ta-toggle-group\" data-role=\"gamme\">\n        <button type=\"button\" data-val=\"C\" class=\"on\">In C major<\/button>\n        <button type=\"button\" data-val=\"G\">In G major<\/button>\n        <button type=\"button\" data-val=\"D\">In D major<\/button>\n      <\/div>\n      <button type=\"button\" class=\"ta-btn\" data-role=\"play\">\u25b6 Play I-V-vi-IV<\/button>\n    <\/div>\n    <div class=\"deg-row\" data-role=\"row\"><\/div>\n    <div class=\"readout\" data-role=\"readout\">The top line (degrees) never changes. The bottom line (actual chords) follows the scale. That&#8217;s transposing.<\/div>\n    <p class=\"svg-caption\">I-V-vi-IV: in C that gives C-G-Am-F, in G that gives G-D-Em-C. Same chart, different outfit.<\/p>\n  <\/div>\n\n  <p>It&#8217;s also musicians&#8217; common language. If the singer tells you &#8220;it&#8217;s too high, go down a step,&#8221; you don&#8217;t relearn anything: the degree chart stays identical, you move your starting scale. Nashville session musicians pushed the idea to writing songs only in numbers (their &#8220;Nashville Number System,&#8221; an Arabic numeral variant), to change keys at the last moment without rewriting a line.<\/p>\n<\/section>\n\n<!-- ============ H2 : rep\u00e9rer ============ -->\n<section id=\"reperer\">\n  <h2>5. Spot degrees in your songs<\/h2>\n\n  <p>Take a song you already play and its chord chart. First question: what&#8217;s the scale? A good clue: the last chord of a piece is often the rest chord, degree I. It&#8217;s not an absolute rule (some pieces deliberately end in suspense), we&#8217;ll see how to really identify the tonic in <a href=\"\/en\/music-theory-for-guitar\/key-and-tonality-guitar\/\">tonality, the center of gravity of a piece<\/a>. But as a starting point, it works very often.<\/p>\n\n  <p>Then translate each chord into a degree. C-G-Am-F? That&#8217;s I-V-vi-IV in C major. And there, something happens: you&#8217;ll find the SAME patterns everywhere. Dozens of songs you thought were different use the same degree chart. You&#8217;ll never read a chord chart the same way again.<\/p>\n\n  <p>To check your translations and <a href=\"https:\/\/twelve-assistant.com\/en\/applications\/key-degrees-analyzer-en\/\" data-track=\"wp-link-scale-degrees-to-key-degrees-analyzer\">visualize degrees in all keys<\/a>, Twelve Assistant&#8217;s Key Degrees Analyzer displays degrees and their chords for each major scale.<\/p>\n<\/section>\n\n<!-- Encadr\u00e9 pratique -->\n<section class=\"guitar-tip\">\n  <h3>On your guitar: three challenges this week<\/h3>\n  <p><strong>Challenge 1.<\/strong> Play a I-IV-V-I in three different scales (C, G, D). Use the method: count the scale notes to find each chord.<\/p>\n  <p><strong>Challenge 2.<\/strong> Take a song you know and translate its chart into degrees. If you land on I-V-vi-IV or vi-IV-I-V, welcome to the club: you just saw the skeleton.<\/p>\n  <p><strong>Challenge 3.<\/strong> Sing the major scale and stop on the 7th note. Feel the leading tone&#8217;s pull, then resolve. Do it three times: your ear just learned the most important tension in tonal music.<\/p>\n  <p>Want to go faster? You can build these progressions directly in <a href=\"https:\/\/twelve-assistant.com\/en\/applications\/progression-guitar-editor-en\/?utm_source=blog&amp;utm_medium=article&amp;utm_campaign=scale-degrees-en&amp;utm_content=inline-link#live-demo\" data-track=\"wp-link-scale-degrees-to-progression-guitar-editor\">the guitar progression editor<\/a>, and pick Lego and Simple chord shapes there.<\/p>\n<\/section>\n\n<!-- FAQ -->\n<section id=\"faq\">\n  <h2>Frequently asked questions about scale degrees<\/h2>\n\n  <div class=\"faq-item\">\n    <p class=\"faq-question\">What is a degree in music?<\/p>\n    <p class=\"faq-answer\">A degree is the numbered position of a note inside a scale. The major scale having 7 notes, it has 7 degrees, numbered I to VII. In C major, C is degree I, D is degree II, E is degree III, and so on up to B, degree VII. The degree describes a relative function: degree I is always the scale&#8217;s starting and rest note, whatever the key.<\/p>\n  <\/div>\n\n  <div class=\"faq-item\">\n    <p class=\"faq-question\">Why do we use Roman numerals in music?<\/p>\n    <p class=\"faq-answer\">We use Roman numerals to designate degrees without confusing them with fret, finger, or string numbers. They also allow indicating chord quality: uppercase signals a major degree (I, IV, V) and lowercase a minor degree (ii, iii, vi). Thus a progression notated I-V-vi-IV reads and transposes in any key, without depending on concrete chord names.<\/p>\n  <\/div>\n\n  <div class=\"faq-item\">\n    <p class=\"faq-question\">What is a I-IV-V progression?<\/p>\n    <p class=\"faq-answer\">A I-IV-V progression chains the chords built on degrees I, IV and V of a major scale. In C, this gives C, F, G; in D, this gives D, G, A. It&#8217;s the most widespread progression in popular music, from blues to rock, because it connects tonality&#8217;s three pillars: the tonic (I), the subdominant (IV) and the dominant (V). Since the distances between these degrees are fixed, the progression sounds identical in all keys.<\/p>\n  <\/div>\n\n  <div class=\"faq-item\">\n    <p class=\"faq-question\">How do you transpose a chord progression with degrees?<\/p>\n    <p class=\"faq-answer\">To transpose, you first translate the progression into degrees, then replay it from another key. For example, the progression I-V-vi-IV gives C-G-Am-F in C major, and G-D-Em-C in G major: the degree pattern is the same, only the starting key changes. You just need to know the major scale of the new key to instantly find each chord. You don&#8217;t relearn anything, you move a pattern.<\/p>\n  <\/div>\n\n  <div class=\"faq-item\">\n    <p class=\"faq-question\">What&#8217;s the difference between tonic, subdominant and dominant?<\/p>\n    <p class=\"faq-answer\">These are the major scale&#8217;s three most important degrees and their functions. The tonic is degree I, rest note and tonality&#8217;s center of gravity. The subdominant is degree IV, which moves away from rest. The dominant is degree V, which creates tension calling for a return to the tonic. This play of rest and tension between I, IV and V is the engine of most progressions and cadences.<\/p>\n  <\/div>\n<\/section>\n\n<!-- R\u00e9cap -->\n<section id=\"recap\" class=\"summary\">\n  <h2>Summary<\/h2>\n  <ul>\n    <li><strong>A degree equals a note&#8217;s number in the scale<\/strong>, in Roman numerals from I to VII. It describes a relative role, not a fixed note.<\/li>\n    <li><strong>Qualities are automatic in major<\/strong>: I, IV, V major; ii, iii, vi minor; vii\u00b0 diminished. Numeral case indicates it (most common convention).<\/li>\n    <li><strong>Three functions<\/strong>: tonic (I, rest), subdominant (IV, movement), dominant (V, tension). The round trip I-IV-V-I tells a complete story.<\/li>\n    <li><strong>The leading tone (VII)<\/strong> is one semitone below the tonic: it&#8217;s magnetized toward it. It&#8217;s the major scale&#8217;s spring.<\/li>\n    <li><strong>Thinking in degrees equals transposing without relearning<\/strong>: the I-V-vi-IV chart plays in all twelve major scales by just changing the starting note.<\/li>\n  <\/ul>\n  <p>You no longer read chord names. You read roles. Next up: actually building these chords, note by note.<\/p>\n<\/section>\n\n<!-- CTA s\u00e9rie (r\u00e9trofit @marketing) -->\n<div class=\"series-cta\">\n  <h3>See the degrees of each key<\/h3>\n  <p>You just understood degrees. The Key Degrees Analyzer displays degrees and their chords for each key, right in your browser. No account, no credit card.<\/p>\n  <a class=\"ta-btn\" href=\"https:\/\/twelve-assistant.com\/en\/applications\/key-degrees-analyzer-en\/?utm_source=blog&amp;utm_medium=article&amp;utm_campaign=scale-degrees-en&amp;utm_content=cta-demo-end#live-demo\" data-track=\"wp-link-scale-degrees-to-key-degrees-analyzer-cta\">Open demo<\/a>\n<\/div>\n\n<!-- Navigation s\u00e9rie -->\n<div class=\"series-nav\">\n  <h3>Continue the series<\/h3>\n  <p>You now know that each degree carries a chord, major, minor or diminished. But where do these chords come from? Why three notes and not two? Why C-E-G and not C-D-E?<\/p>\n  <p>It&#8217;s time to stack the scale notes and build your first chords while understanding what you&#8217;re doing.<\/p>\n  <a class=\"ta-btn\" href=\"\/en\/music-theory-for-guitar\/guitar-chord-construction\/\">Article 6: Guitar Chord Construction \u2192<\/a>\n  <span class=\"prev\">\u2190 Previous: <a href=\"\/en\/music-theory-for-guitar\/guitar-scales-explained\/\">Article 4: Guitar Scales<\/a> \u00b7 <a href=\"\/en\/music-theory-for-guitar\/\">Back to music theory table of contents<\/a><\/span>\n<\/div>\n\n<\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>You&#8217;ve already encountered these odd notations on a forum or app: I-IV-V, ii-V-I, I-V-vi-IV. Roman numerals everywhere, and everyone seems to understand. Good news: it&#8217;s the simplest and most powerful system in all of music theory. You know the major scale and its formula? Then you only need one thing: give a number to each [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2214839,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"tpl-cours.php","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-2214844","page","type-page","status-publish","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.1 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Scale Degrees for Guitar: The I-IV-V System<\/title>\n<meta name=\"description\" content=\"Understand chord progressions with Roman numerals. 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