What does this symbol mean?

[andersand]

Hi. In Debussy's arabesque 1, bar 19 and 20, there are this strange symbol like an x in front of the F, what does it mean?

Is there an online reference where you can look up all kinds of things that might appear in a sheet? I've searched but it's hard to find specific things when you don't know what to call them.

[mdshimazu]

That's a double sharp. Play the note G instead of F(bring the F up 2 half steps).

[andersand]

Ahhh... thank you.
I'm glad i asked, it would have been sad to play those notes wrong over an over again.

[danny elfboy]

Is there an online reference where you can look up all kinds of things that might appear in a sheet? I've searched but it's hard to find specific things when you don't know what to call them.

Accidentals
Ornamentations
Phrasing and Articulations