C7#5

— About this chord

C7#5 (1-3-♯5-♭7), also called Caug7, raises the 5th of a dominant seventh for a restless, whole-tone-flavored tension that pulls hard toward resolution. A classic jazz turnaround color, it often substitutes for a plain V7 to add chromatic motion into the tonic, giving standards and blues changes a sly, sophisticated edge. On guitar it's typically fretted as a compact four-note shape with the root on the A string, or moved down to a low-string voicing for a darker register. Frequently used in ii-V-i cadences and as a passing chord walking up to the IV or vi. Also searched as C7+5, Caug7, or C dominant 7 sharp 5.