C#add9

General info

Full name

C# Add9

Symbol

C#add9

Root

C#

Quality

Add9

Chord notes

Functions & resolutions

Typical function in key

ITonic (I)C# major

Stability / tension

Stable — can serve as major tonic

Most common resolutions

F#F# MajorG#G# MajorA#mA# Minor

Main resolution

C#add9source

G#G# Major

Major chord C# is a stable tonic. As tonic it doesn't require resolution, but in a progression context typically moves to IV or V.

Other resolutions

C#add9source

Deceptive resolution

A#mA# Minor

As the V degree, a major chord can defy expectations by moving to vi instead of I (deceptive cadence).

C#add9source

Modal resolution

BB Major

In modal context, a major chord can freely move to bVII, bIII, or bVI — characteristic of Mixolydian mode.

C#add9source

Jazz reharmonization

C#maj7C# Major 7

In jazz, a major chord is enriched to maj7, 6/9, or add9 and can smoothly transition into a ii-V of another key (modulation).

C#add9source

Functional resolution

G#G# Major

As the IV degree (subdominant), a major chord can resolve to V or directly to I (plagal cadence).

Features

Character

Major, with an added 9th and no 7th

Characteristic interval

9th without 7th (add9)

Description

A major 9th is added to a major triad without a 7th. The chord retains a simple triadic core while adding second-based tension between root and 9th.

Application

• Added-tone major tonic
• Pop and rock
• Arpeggiated textures

Voicing & structure

Harmony

Compatible scales

All chord tones are contained in these scales — use them for improvisation.