Your job is to make a music playing device. Here's the task list:

Points	Task
3	Registers a major number
3	Can be written to
6	Rejects any write that contains any byte outside of A-G (all uppercase) or 1-9
6	Makes a sound
6	Makes different notes when different letters are sent
6	Can play "Mary Had A Little Lamb"
6	The digits 1-9 change the duration of following notes
6	Octave changes
2	has an 'r' for rest
10	Has a clear top and bottom half
5	Uses some locking something to regulate data changes
10	Can play a sound and receive data at the same time
10	Uses either a circular buffer or a linked list to hold requests (or something else that's O(n) and approved by me).
5	Has a status file describing the current amount of notes in the queue, and the metadata for the data structure. For a linked list ... number of links and their addresses For a circular buffer ... head and tail pointers

Here's a list of frequencies

Note Frequency

A 220

B 247

C 262

D 294

E 330

F 349

G 392

Here's the notes of "Mary Had a Little Lamb"
EDCDEEEDDDEGGEDGDEEEEDDEDG