The B Add 9 chord is a four-note chord made up of B, D♯, F♯, and C♯. It is built from a root, major third, perfect fifth, and major ninth.
Construction
B Add 9 = Root + Major 3rd + Perfect 5th + Major 2nd = B · D♯ · F♯ · C♯
| Note | Interval | Degree |
|---|---|---|
| B | Root | 1 |
| D♯ | Major 3rd | 3 |
| F♯ | Perfect 5th | 5 |
| C♯ | Major 2nd | 2 |
B Add 9 Inversions
| Position | Notes |
|---|---|
| Root Position | B – D♯ – F♯ – C♯ |
| 1st Inversion | D♯ – F♯ – B – C♯ |
| 2nd Inversion | F♯ – B – C♯ – D♯ |
| 3rd Inversion | B – C♯ – D♯ – F♯ |
Key Signature
A chord has no key signature of its own, but the B Add 9 is the tonic (I) chord of B Major, whose key signature has 5 sharps (F♯, C♯, G♯, D♯, A♯).
F♯C♯G♯D♯A♯
Order of sharps
Sharps are added to a key signature in a fixed order. Each new sharp key adds the next sharp on the list.
F♯C♯G♯D♯A♯E♯B♯
Mnemonic: Father Charles Goes Down And Ends Battle
Chords in the Key of B Major
These are the triads built on each degree of the B major scale:
Same Notes, Other Names
The notes B – D♯ – F♯ – C♯ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell:
B Add 9 — Frequently Asked Questions
What is the B Add 9 chord on piano?
The B Add 9 chord contains the notes B – D♯ – F♯ – C♯. On piano, play these notes together to sound the chord.
What notes are in the B Add 9 chord?
The B Add 9 chord (Badd9) contains four notes: B (root), D# (major third), F# (perfect fifth), and C# (major ninth). No seventh — the ninth adds brightness to the triad.
How does Badd9 differ from B9?
Badd9 has no seventh. B9 includes the minor seventh (A). Badd9 is bright and open; B9 is dominant and bluesy.
How is Badd9 used in music?
Badd9 substitutes for B Major in rock, pop, and acoustic music. B Major is common in contemporary worship and pop-rock.
What songs use add9 chords?
Add9 chords appear in Wonderwall (Oasis), Good Riddance (Green Day), and countless pop songs.
How does Badd9 differ from Bsus2?
Both contain B and C#. Badd9 keeps D# (major third); Bsus2 replaces it. Badd9 is major with colour; Bsus2 is ambiguous.
Can I substitute Badd9 for B Major?
Yes — Badd9 replaces B Major in most pop contexts for added shimmer.