If you start
playing from the note D, and play eight notes, that
is the scale of D major.
F sharp G
C sharp D
the play arrow twice.
At the beginning of this, you will see the key signature with two sharps,
indicating that in this piece of music all the F notes are sharps and all
the C notes are sharps. Instead
of the white note F, you play the black note F sharp. Instead of the white
note C, you play the black note C sharp. The F sharps and the C sharps are
just to the right of the C and F notes.
On this keyboard, the F sharps and the C sharps are indicated.