Correction to the comments in the code of the OP.
The comment for notes //1, //7, //13 & //20 should be 3/16 not 3/18.
I was unable to figure out how to set the length of a note to 3/16 or 3/4.
Here's the list I found, as noted in the OP link for Decimal Command Codes:
http://www.parallax.com/Portals/0/Downloads/docs/prod/audiovis/27976-7-9-ParallaxSerialLCD-v3.0.pdf
Dec Hex Action
208 D0 Set note length to 1/64 note
209 D1 Set note length to 1/32 note
210 D2 Set note length to 1/16 note
211 D3 Set note length to 1/8 note
212 D4 Set note length to 1/4 note
213 D5 Set note length to 1/2 note
214 D6 Set note length to whole note (2 seconds)
MY SECOND QUESTION: Does anyone know how to set the length of a note to 3/16 and 3/4?