Nocturne No.21 in C minor Op.posth 8. Nocturne No.21 in C minor, Op.posth Nocturne No.20 in C sharp minor Op.posth Nocturne in C minor op.pist. Nocturne No. 20 in C-sharp minor, op. posth Nocturne No.20 in Sharp Minor,Op.Posth Nocturne No.20 in C sharp minor, Op.post. Nocturne No.20 in C sharp minor,Op.posth. No.21 in c minor,op.posth Nocturne no. 13 in C minor, op. 48 no. 1