Notation question natural followed by sharp Chopin Waltz in C sharp minor

In Chopin's Waltz in C sharp minor, I'm a bit confused by the following notation:

The F has a natural, cancelling out the sharp in the key signature. But then it instantly becomes an F-sharp again. Once more there is no note to play for the accidental, so I don't understand what this piece of notation is telling me.

I would guess I play the F natural and then the G, then the next F in the bar I play as an F-sharp?

Thank you.

• Is this a published version or a reprint? If it’s a reprint it may be a typo, possibly F natural and G sharp. Sep 11, 2020 at 14:55
• @JohnBelzaguy it is a reprint. Your suggestion makes sense! Sep 11, 2020 at 14:56
• Maybe there is a G natural in the preceding bars which would account for the courtesy accidental on the G... Sep 11, 2020 at 14:57
• @JohnBelzaguy Looking back at the previous bar. There is an F double sharp. So would the accidental flatten it to an F and the sharp make it an F sharp again? Not sure. Sep 11, 2020 at 14:59
• There’s your answer by @mattputnam, +1. The natural-sharp in your version is an odd way to cancel a double sharp. I think his version is much easier to read, after all we’re all supposed to know that an accidental is good only for the bar it’s in, right? ;) Sep 11, 2020 at 15:10

The previous measure has an F double-sharp:

The natural-sharp is to remind you that it's no longer double sharp.

• Obviously the correct answer - made more clear with sight of the previous bar - as suspected, Fx. However, the OP's copy is poor. There's really no need for anything, but if someything was put in, it needed to be in parentheses, as a cutionary, surely? +1
– Tim
Sep 11, 2020 at 15:17
• Yes, the original score is bad practice - a # in front of an f means f sharp, NQA, no matter what the context and the key signature is. Writing "natural + accidental" just confuses this rule. Sep 11, 2020 at 15:24
• Natural-sharp like this is actually pretty common and not usually an issue. I don't like it here, mainly because with the F-G cluster it's easy to think one of the accidentals is for the F and the other is for the G (in this case, it would be F-natural and G#). Parentheses are optional. Sep 11, 2020 at 15:42

You need to look at the previous bar as well. There's a Fx (F double-sharp). Technically, this reverts to the single sharp of the key signature in the next bar. Some editions therefore omit any accidental. Some (like the one below) add a cautionary # on the F. Your example uses the old convention of cancelling a double-sharp with a natural-sharp.

Either way, the note in question is F♯. The other note in the dyad is G♯, according to the key signature. And it IS a dyad, a two-note chord. To be played together. The offset - one note each side of the stem - is purely to avoid an ugly printing collision.

To address the last part of your question - both the F(♯) and G(♯) are played at the same time - they just got printed to look like they do, as there isn't room on one side of the stem! Don't ever think of playing them one after the other - that's not correct.