Imaj7

Imaj7, shorthand for the major seventh on the first scale degree, is a four-note chord built from a major scale: root, major third, perfect fifth, and major seventh above the root. It is the diatonic tonic seventh chord in any major key and is often written as Imaj7 or I△7.

In C major, the notes are C E G B; in G major, G B D F#, in A major, A C# E G#. The presence of the major seventh interval above the root gives the chord a lush, jazzy color and a smoother resolution than a plain major triad.

Functionally, Imaj7 provides tonic stability with a soft, dreamy quality. It is widely used in jazz, pop, and film music. Common progressions include Imaj7 moving to IVmaj7 or II7–V7–I, with the Imaj7 serving as a rich tonal center.

Voicings vary from root position (1–3–5–7) to various inversions and drop-2 shapes. Jazz players may add tensions, such as 9 or 11, or use substitute voicings, but the defining sound remains the major seventh above the root.