Added a yellow cursor controlled by the user with the arrow keys. Pressing the TAB key switching the cursor between the music staff and the tab.

Notes can be placed and removed using the spacebar.

Notes below the range of a standard tuned guitar are shown in red.

Notes can be placed from E2 to E7. Legder lines are drawn automatically when necessary.

When consecutive notes are place (E and F in the picture), the higher one is mirrored so they don't overlap. This works for as many notes as you want. However, the maximum number of notes that can be placed in a single column is six, as there are only six guitar strings.

Flats can be placed and removed with the minus sign, sharps with the plus sign. The equal sign clears them both and may be used later for the natural sign.

I'm currently working on allowing the user to type in tab numbers, but here's an example of what it will look like.

Also, F2 clears the whole screen.