Finger Positions

Root Note C#

Name C# half-diminished over A#

Intervals 1P-3m-5d-7m

Relative Minor A#m

Notes A#, C#, E, G, B

Aliases C#m7b5, C#ø, C#-7b5, C#h7, C#h

How to play the C#m7b5/A# Chord

The C#m7b5/A# is a fundamental dominant chord in guitar music. To play this chord correctly, ensure your fingers are placed precisely on the frets indicated in the diagram above.

Music Theory Analysis

From a theoretical perspective, the C# half-diminished over A# is built using the 1P, 3m, 5d, 7m intervals. In the key of C# Major, this chord functions as the I chord.

Common Progressions

In music composition, the C#m7b5/A# chord is often used to create tension or resolution.

I-V-vi-IV

C# → G# → A#m → F#

vi-IV-I-V

A#m → F# → C# → G#

The Diatonic Family

Understanding the "family" of chords that belong to C# helps with transposition and ear training.

Triads

C# D#m Fm F# G# A#m Cdim

7ths

C#maj7 D#m7 Fm7 F#maj7 G#7 A#m7 Cm7b5

Scale Compatibility

View All Scales

Minor Blues Locrian Locrian Pentatonic Super Locrian Pentatonic Altered Locrian #2 Locrian 6 Dorian #4 Hungarian Major Flamenco Bebop Locrian Half-Whole Diminished Composite Blues Messiaen's Mode #3 Chromatic

* 15 scales found containing the notes A#, C#, E, G, B.

Acoustic & Digital Analysis

Digital footprint of the C#m7b5/A# chord for MIDI programming and synthesizer sound design.

MIDI Numbers 70, 61, 64, 67, 71

Frequencies (Hz)

466.1637615180899, 277.1826309768721, 329.6275569128699, 391.99543598174927, 493.8833012561241