Advaced sheet music readers help please!?

Question

Ok i am learning 3 songs. One is by Chopin, One By Liszt, and One by Rachmaninoff. And in all 3 songs there are little x's next to certain notes. I have absolutely no idea what their function is. Can anyone please tell me what they are?

Answer 1

Double sharp.

As opposed to a double flat (bb)

In case you run into those later..

Answer 2

what instrument?

Answer 3

Double sharp. Sharp it once and then sharp it again and you'll have the right note. You should be a whole step higher.

Answer 4

Adrienne is correct.  It's a double sharp.  And that answer is the same for every instrument (except maybe percussion, which sometimes actually uses notes that look like and X with a stem).