Nocturne No.16 C-Sharp Minor, Op. posth. Nocturne in C-sharp minor, op. posth Nocturne No. 20 in C-sharp minor, op. posth Nocturne in C-sharp minor,op.posth. Nocturne No. 20 in C sharp minor, op. post. Nocturne No.20 in C sharp minor, Op.post. Nocturne No.20 in C sharp minor,Op.posth. Nocturne No.20 in C sharp minor,Op.osth. Nocturne in C sharp minor op.post Nocturne No.20 in C sharp minor Op.posth