Step 6:

Making the tuning holes
 this part is complicated.
A little more on music so bear with me.
(for the purposes of the instructable)
music notes start with a C, then D,E,F,G,A,B and the next C up.
This is called an octave (8 notes).
If you did everything correctly you should be getting a C5 on the tuner which is
one octave above middle C (C4, middle C is the middle C key in a keyboard)

Thing to keep in mind while drilling your tuning holes, start with a small hole and increase the size until you hit the desired note.

The holes are #1 top right, #2 bottom right, #3 top left, and #4 bottom left.

their placement isn't too critical

Start with the #1 hole and start small and keep going up in size till you hit a D note.Remember to clean the holes with 150 sandpaper after drilling.
Then continue with hole #2. To tune #2 you have to cover #1 (the one we just made) keep going to you hit an E note.
(you get an F by leaving 1& 2 open incase you were wondering)
Now the #3 hole. To tune the #3 hole you must cover the #2 hole and leave the #1 open until you get a G
For the 4th and final hole you can cover hole #1 and tune for B or leave them all open and tune for a C.
If the last note doesn't seem to work try blowing softly.

Once your done tuning it. Glue the top on and carve out a mouth piece to make it comfortable to blow on.