The previous article covered the major scale and how it gets numbered. This article covers how chords get built from those scales — the basic triad construction, the chord types that actually appear in bluegrass, and the no-third voicing tradition that gives bluegrass guitar in particular its distinctive sound.

The major triad: 1, 3, 5

A chord is two or more notes played together. A triad is the simplest kind of complete chord — three notes from the scale, stacked in thirds. To build a major triad from any scale, you take three specific scale degrees: the 1, the 3, and the 5.

In G major, those notes are:

• 1: G
• 3: B
• 5: D

Play G, B, and D at the same time and you have a G major chord. On a guitar, the open-position G chord (the one most beginners learn first, fingered low-to-high as G-B-D-G-B-G) is exactly this — the same three notes, with several octaves of G and B added in for fullness.

This pattern of “1, 3, 5 from the major scale” gives you the basic vocabulary of major chords. The 4 chord (C major) is built on C-E-G, the 1-3-5 of the C major scale. The 5 chord (D major) is built on D-F♯-A, the 1-3-5 of the D major scale.

The minor triad: 1, flat 3, 5

A minor triad takes the same shape but lowers the middle note by a half step:

• 1: G
• flat 3 (or “♭3”): B♭ (B-flat)
• 5: D

That is a G minor chord. The flat 3 is what makes a chord sound minor rather than major. Everything else (the root, the 5) stays the same.

In Nashville Numbers, minor chords are written with a small “m” after the number: 6m, 2m. The 6m chord in G is E minor (E-G-B). The 2m chord in G is A minor (A-C-E).

The dominant 7 chord: 1, 3, 5, flat 7

The dominant seventh chord adds a fourth note to the major triad — the flat 7 of the scale. In G it is:

• 1: G
• 3: B
• 5: D
• flat 7: F (the F natural, not F♯)

That is a G7 chord. The flat 7 adds an unresolved, “wanting to move” quality that classical theory calls “dominant function.” Dominant 7 chords pull strongly toward their fourth above. A G7 chord wants to resolve to a C chord; a D7 chord wants to resolve to a G chord.

This pull is the basis of the most common cadence in bluegrass: the V7 to I. In a song in G, the 5 chord (D) is often played as a D7 (the dominant V7), and it resolves back to the 1 (G). Written in Nashville Numbers: “5-7 to 1,” or just “5 to 1” with the understanding that the 5 is a dominant 7.

Bluegrass musicians use the dominant 7 chord in two main places:

1. As the V7 cadence chord — the 5-7 to 1 resolution that ends most bluegrass songs. Universal.
2. As an “I7” in blues-flavored songs — the 1 chord itself played as a dominant 7, which pulls toward the 4. This is the bluesy sound on songs like “Mule Skinner Blues” or “Salty Dog Blues.”

The chord types that actually appear in bluegrass

The full vocabulary of chord types in classical and jazz theory runs to dozens of variants. Bluegrass uses a small subset.

• Major triads — overwhelmingly the most common. The 1, 4, and 5 in any given key. You can play most bluegrass songs with these three chords.
• Dominant 7 — very common as the V7 cadence; also as 1-7 in bluesy material.
• Minor triads — occasional. The 6m is the most common minor; the 2m appears in gospel-flavored material and newgrass.
• Suspended 4 (sus4) — the 3 is replaced with the 4. Common as a passing ornament on transitions.
• The flat 7 chord (♭VII) — the chord built on the flat 7 of the scale. Defines the modal “flat 7 sound” on tunes like Old Joe Clark and Cripple Creek.

Other chord types are essentially absent from traditional bluegrass:

• Major 7 chords (like Gmaj7 = G-B-D-F♯) — rare in trad bluegrass, common in newgrass and the Colorado sound. The jazzy major-7 sound is generally avoided in the trad context.
• Minor 7 chords — same. Rare in trad, common in newgrass / Dawg / contemporary instrumental.
• Diminished and augmented chords — essentially absent. The Mandolin Cafe and Banjo Hangout forum consensus: “9ths, 11ths, 13ths, diminished and augmented chords are unusual in bluegrass or old-time music.”
• 9, 11, 13 extensions — absent in trad. Defining feature of newgrass and Dawg.

One way to think about it: bluegrass harmonic vocabulary is intentionally narrow. The music’s expressive depth comes from the melody, the rhythm, the timbre of the instruments, and the close-harmony vocal stack — not from harmonic sophistication. A song with three chords played at the right tempo with the right drive is more bluegrass than a song with nine chords played politely.

The bluegrass major: voicings without the third

One of the genre’s distinctive harmonic features is a tradition, especially on guitar, of voicing major chords without the third — that is, leaving out the note that defines the chord as major or minor. The result is an ambiguous, modal-leaning sound that fits the older mountain-music aesthetic the genre inherited.

The clearest case is the bluegrass G chord on guitar.

The bluegrass G chord

The standard open G chord on guitar is fingered low-to-high as 3-2-0-0-0-3 (low E at fret 3, A at fret 2, D, G, and B open, high E at fret 3). The notes that sound, low to high, are G-B-D-G-B-G — the 1, 3, and 5 of G major, with the 3 (B) doubled.

The bluegrass G chord changes two notes. The A string is muted (not played) and the B string is fretted at 3, so the chord is fingered 3-X-0-0-3-3. The notes that sound are G-D-G-D-G — nothing but roots and 5s, with the 3 gone entirely. This is the “modal G.”

Tony Rice articulated the principle in a Premier Guitar lesson piece: he could play a regular G with no third, then move to B-flat, C, or F, “and it will work with all those chords.” The bluegrass G doesn’t commit to major or minor; it acts as a drone that fits over the harmonic motion underneath. Bluegrass guitar players sometimes refer to this voicing as the “modal G” for the same reason.

Why no third?

Two related reasons. First, the older mountain music bluegrass came out of was modal-leaning — the melodies often used neither a clear major nor a clear minor third, and the accompanying instruments (fiddle drones, banjo modal tunings) reflected that. Second, leaving the 3 out gives the chord a brighter, “ringier” sound on a steel-string guitar: the notes that remain are mostly the 1 and the 5, which are consonant intervals that ring strongly together.

The fiddle world has a parallel tradition. Bluegrass fiddlers regularly play double-stops in three standard combinations: 1+5, 1+3, and 3+5. The 1+5 double-stop is the no-third version — the same drone-flavored sound the bluegrass G chord makes on guitar. Mitch Reed’s fiddle instructional materials and the Fiddle Hangout community both describe the 1+5 double-stop as “open-ended dramatic, folk/primitive.”

The mandolin chop chord has elements of the same logic. Some chop voicings include the 3; some omit it, particularly 2-note and reduced variants. The chop’s primary function is percussive, not harmonic, so the chord content can be reduced without losing the role.

The bass plays root-and-fifth as its default pattern (root on beat 1, fifth on beat 3) and stays out of the major/minor question almost entirely. This is documented in every bluegrass bass instructional source. Walking lines between chords use scale degrees, but the foundational pulse is 1-and-5.

Where the no-third tradition runs through the band

If you assemble the parts: guitar plays a bluegrass G with the third reduced, mandolin chops with a percussive (often reduced) voicing, bass plays root-and-five, fiddle plays a 1+5 double-stop drone. The third — the note that would define the chord as cleanly major or minor — is often the singer’s part to provide, or sometimes the banjo’s. The rest of the band leaves the chord harmonically open. This is what gives bluegrass its modal-leaning rhythmic backdrop, even on songs that are nominally major-key.

How explicitly any individual player thinks about this varies. Most working players are not articulating a “no third” rule; they are using voicings they learned from records and from other players that happen to leave the third out. The pattern is real, but the working musician’s framing is more “this sounds right” than “I’m dropping the chord’s defining note.”

Other voicings worth knowing

The bluegrass C chord

The standard open C chord on guitar is fingered X-3-2-0-1-0, sounding C-E-G-C-E. Many bluegrassers use the low G in the bass: 3-3-2-0-1-0, sounding G-C-E-G-C-E. This is a C with G in the bass — the 5 of the chord underneath instead of the root — which sets up the bass note to alternate between the 1 and the 5.

The bluegrass D chord

The standard open D chord on guitar is X-X-0-2-3-2, sounding D-A-D-F♯ with the F♯ (the 3) at fret 2 of the high E string. Many bluegrassers voice the D chord with no thirds. They play X-0-0-2-3-X with the A note (the 5) in the bass, and alternate the bass note between the 1 on the D-string and the low A.

Slash chords and inversions

A “slash chord” specifies a bass note that is not the root of the chord. C/G means “play a C chord, but with G in the bass.” The bluegrass C voicing above (3-3-2-0-1-0) is functionally C/G even when it is not labeled that way.

Bluegrass charts rarely write out slash chords. The convention is to write the chord name (C) and let the bass player or rhythm guitarist play the bass walk that produces the inversion implicitly. The bluegrass G run into a C chord, for example, walks G-A-B-C in the bass — producing brief G/A and G/B inversions on the way — without anyone notating those intermediate chords.

Practical: learning chords for a beginner

The standard bluegrass beginner sequence, across Wernick, the Murphy Method, Steve Kaufman, and Janet Davis:

1. Major triads in the most common bluegrass keys. G, C, D, A as the starter four. (Pete Wernick: “All you need are four basic chords to play along with the band.”)
2. The dominant 7 for the V chord — especially relevant on banjo, where Murphy Method explicitly teaches G, D7, and C as the starter trio because D7 (not D) is what banjo backup actually plays.
3. The minor 6m — the most common minor chord in bluegrass.
4. The flat 7 chord for modal tunes.
5. The major 2 chord as a secondary dominant in gospel and ragtime material.

The deeper article on Chord progressions and chord charts covers how these chord types get strung together into the common bluegrass progressions, and how this site notates them.