The standard grips this chord is usually shown with.
B7 is B, D#, F# and A — B with the flat seventh added on top.
It sounds restless and pointed at something. The third and the flat seventh are a tritone apart and each moves by a semitone into the next chord; that is the engine of a cadence, and the whole vocabulary of the blues.

| B | D# | F# | A |
|---|---|---|---|
| 1 | 3 | 5 | ♭7 |
Dominant — it points a fifth down.
Also written Bdom7 or B dominant 7. The same chord either way; which spelling you meet depends on who wrote the chart.
B7 in 2nd inversion puts F# in the bass instead of B, the 5th of the chord. The notes are the same; what changes is what the bass line does, which is most of why you would reach for it — it lets the lowest voice move by step where the root would have jumped.
One of B7’s 7 common shapes does this: xx4445.
Start with x-x-9-11-10-11 — no barre. 1 of the 7 shapes here sits in open position. 5 of the 7 need a barre. Together they cover the neck from the 1st fret to the 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x21202 | open position | B, root position | F# | barred |
| x24242 | 2nd fret | B, root position | F# | barred |
| xx4445 | 4th fret | F#, 2nd inversion | A | barred |
| 764445 | 4th fret | B, root position | A | barred |
| 797877 | 7th fret | B, root position | B | barred |
| x-x-9-11-10-11 | 9th fret | B, root position | D# | all fretted |
| x-14-13-14-12-x | 12th fret | B, root position | B | all fretted |
The same notes rebuilt from scratch give 5 shell, 14 drop 2, 9 drop 3 and 4 open string voicings, each on its own page.
Tensions. A shell of B7, root, third and seventh, leaves a string free, and the tones that belong over it are the b9 (C), the 9 (C#), the #9 (C##), the #11 (E#), the b13 (G) and the 13 (G#).
B7 is the V of E, and that is where it goes if it goes anywhere: the third and the flat seventh are a tritone apart, and both resolve by a semitone into E.
Voice by voice, B7 → E. 2 voices move by a semitone, and one note is common to both chords.
| In B7 | Moves | In E |
|---|---|---|
| B, the root | stays where it is | B, the fifth |
| D#, the major third | rises a semitone | E, the root |
| F#, the fifth | falls a whole tone | E, the root |
| A, the flat seventh | falls a semitone | G#, the major third |
In which keys. Every note of B7 belongs to C# minor (the ♭VII) and E major (the V, the dominant).
Every note of B7 is in B mixolydian, B lydian dominant and B half-whole diminished.
Change one note of B7 and you have B (drop the flat seventh), Bmaj7 (the flat seventh becomes a major seventh), Bm7 (the major third becomes a minor third), Badd9 (the flat seventh becomes a ninth), B6 (the flat seventh becomes a sixth) or B7sus4 (the major third becomes a fourth).
B7 is a dominant chord — root, major third, fifth, minor seventh. Dominant seventh chords on every root.
On B7’s sound and use this page follows Edward Aldwell & Carl Schachter, Harmony and Voice Leading (Schirmer / Cengage, 4th ed., 2011). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.