C♯ 13 = C♯ · D♯ · F · G♯ · A♯ · B (root, 9th, 3rd, 5th, 6th/13th, 7th). 1336 playable voicings on the standard E9 copedent — the best 12 by neck position below.
Low neck (frets 0–7)
Fret 7 · RKRRKR lowers string 4 a half step (E→D♯); lowers string 5 a half step (B→A♯)Fret 5 · 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 7 · 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 5 · C + LKL + RKRC 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)RKR lowers string 4 a half step (E→D♯); lowers string 5 a half step (B→A♯)
Mid neck (frets 5–12)
Fret 9 · RKLRKL lowers string 2 a half step (D♯→D); lowers string 9 a half step (D→C♯)Fret 9 · AA raises strings 5 & 10 a whole step (B→C♯)Fret 9 · CC raises string 4 a whole step (E→F♯); raises string 5 a whole step (B→C♯)Fret 5 · 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♯)
High neck (frets 10–17)
Fret 11 · B + C + RKRB raises strings 3 & 6 a half step (G♯→A)C 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 17 · 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 16 · B + C + LKLB raises strings 3 & 6 a half step (G♯→A)C 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 17 · C + LKL + RKRC 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)RKR lowers string 4 a half step (E→D♯); lowers string 5 a half step (B→A♯)