The Meaning of the Triangle in Jazz Chord Notation

Understanding jazz chord notation is essential for anyone delving into the world of jazz music. One of the most important symbols to grasp is the triangle. In this article, we will explore the meaning and uses of the triangle in jazz chord notation and the nuances of major 7th chords.

What is a Triangle in Jazz Chord Notation?

In jazz, a triangle (Delta;) typically signifies a major chord. This symbol is used to denote a chord's structure, allowing musicians to quickly understand the harmonic structure of a piece without needing to read out the full chord spelling. The triangle is a shorthand for the three notes of a triad, which forms the foundation of the major chord.

Major Seventh Chord

One of the most common uses of the triangle in jazz chord notation is in a major seventh chord. When a triangle is used in the context of a major seventh chord, it usually appears as 'maj7' or 'M7.' A major seventh chord is a chord where the seventh is a major seventh above the root of the chord. This is in contrast to a dominant seventh chord, which uses a minor seventh.

Comparison of Chords

A major seventh chord is denoted as:

major 7th (maj7) M7 (M for Major) Δ7 (Delta 7) ⑦ (Unicode Triangle)

A dominant seventh chord, on the other hand, uses a minor seventh and would be denoted as:

M7?5 (M for Major, ?5 for a flat fifth)

Types of Major Seventh Chords

There are various types of major seventh chords, each with its unique characteristics. Here are a few examples:

Minor Major Seventh Chord (mM7, mΔ7): A chord with a root minor third, perfect fifth, and a major seventh above the root. Half-Diminished Seventh Chord (m7): A chord with a root minor third, diminished fifth, and a minor seventh above the root. Minor 7th Major 7th Chord (m7M7, m7Δ7): A chord with a root minor third, perfect fifth, and both minor and major sevenths above the root.

Open Guitar Chord Examples

Here are the open guitar chord shapes for comparison:

C7 (Dominant 7th): C-E-G-B (root, major third, perfect fifth, minor seventh) CΔ7 (Major 7th): C-E-G-B (root, major third, perfect fifth, major seventh) CmΔ7 (Minor Major 7th): C-E-G-B (root, minor third, perfect fifth, major seventh)

A CmΔ7 chord would begin on the 3rd fret, but remember, it is a movable shape.

Non-Universal Usage and Confusions

While the use of the triangle in jazz chord notation is widely understood, it is not universally used. In some areas, it is common, while in others, it might lead to confusion. For example, a student's Italian friends might have never seen the triangle and consider it strange or unnecessary.

Additionally, there are disagreements among educators about specific notations. For instance, 'maj' versus 'M' for major chords and 'm' versus 'mi' for minor chords. Some prefer to use lowercase 'm' for minor, while others suggest using uppercase 'M' for major to avoid confusion.

Standardization Efforts

Attempts have been made to standardize jazz chord symbols. One example can be found on the Jamey Aebersold website, which provides a standardized listing of jazz nomenclature. This section of the website aims to create clarity and consistency in chord notation.

Ultimately, the use of the triangle in jazz chord notation is a tool that can greatly enhance musical communication, but it is important to be aware of the nuances and potential misunderstandings.