C7(#11) chord on guitar
C7(#11) is the dominant sharp eleventh chord: C, E, G, Bb and F# (1–3–5–b7–#11). On guitar, the diagram shape is 0 1 4 0 1 0, with E in the bass.
On the guitar, six strings give the chord room to breathe — some positions use them all, others ask you to mute the lowest ones. In this C7(#11) voicing the bass is E and the shape runs from fret 1 to 4, ringing 3 open strings. Its hollow wooden body gives every chord a warm, natural ring that blooms and fades on its own.
Notes and formula of C7(#11)
Notes in C7(#11): C – E – G – Bb – F#Formula: 1 – 3 – 5 – b7 – #11In the formula, the numbers count steps of the major scale starting from the note that names the chord; "b" lowers a half step, "#" raises one — and a slash names the bass note.
Where to use it
You hear it a lot in jazz and bossa nova turnarounds — which simply means those short chord loops that close a section and set up the restart. It is also a classic ending color: a last chord that sounds like a question mark instead of a period.
See also
Part of the Altered dominants family.