About the C sharp major seven sharp five chord
The C sharp major seven sharp five chord is a C sharp major seventh sharp five built from C sharp, E sharp, G double sharp, B sharp. You will most often meet it as the I+ chord in C sharp Lydian Augmented.
It is also written D flat major seven sharp five , which spells the same notes enharmonically.
In shorthand it is commonly written C#maj7#5.
Inversions
(root position)
Notes and intervals
| 1 | C sharp | Root |
| 2 | E sharp | Major 3rd |
| 3 | G double sharp | Augmented 5th |
| 4 | B sharp | Major 7th |
Shapes
Chromatic
Circle of Fifths
Keys that use C sharp major seven sharp five
C sharp major seven sharp five is diatonic to these keys, where it acts as the chord shown.
Other C sharp chords
Simpler triads
Suspended
Sixths and sevenths
Extensions
Altered
Functional relationships
These chords are where this one most naturally comes from and resolves to inside a key.
Relative minor
The relative minor uses the same notes and key signature, so it works as a calmer, darker home base.
Parallel minor
The parallel minor keeps the same root note but lowers the third, giving the same key a darker, sadder sound.
Dominant
The dominant is a fifth above the root, and it builds tension that pulls strongly back to this chord.
Subdominant
The subdominant is a fourth above the root (a fifth below), and it usually leads on to the dominant or back home.
Tritone substitution
The tritone substitution stands in for this chord's dominant with a dominant seventh a half step above the root, which slides down by a half step to resolve here.
