C maj11 = C · D · E · F · G · B (root, 9th, 3rd, 11th, 5th, 7th). 23 playable voicings on the standard E9 copedent — the best 5 by neck position below.
Low neck (frets 0–7)
Fret 6 · LKL + RKRLKL raises strings 4 & 8 a half step (E→F)RKR lowers string 4 a half step (E→D♯); lowers string 5 a half step (B→A♯)Fret 0 · C + RKRC raises string 4 a whole step (E→F♯); raises string 5 a whole step (B→C♯)RKR lowers string 4 a half step (E→D♯); lowers string 5 a half step (B→A♯)
Mid neck (frets 5–12)
Fret 9 · C + LKLC raises string 4 a whole step (E→F♯); raises string 5 a whole step (B→C♯)LKL raises strings 4 & 8 a half step (E→F)Fret 12 · C + RKRC raises string 4 a whole step (E→F♯); raises string 5 a whole step (B→C♯)RKR lowers string 4 a half step (E→D♯); lowers string 5 a half step (B→A♯)Fret 11 · A + LKL + RKRA raises strings 5 & 10 a whole step (B→C♯)LKL raises strings 4 & 8 a half step (E→F)RKR lowers string 4 a half step (E→D♯); lowers string 5 a half step (B→A♯)