Develop a musical composition based on the provided pattern of letters and incorporating the given motif within it.
X:1
L:1/8
M:4/4
K:G
['E AAA z BcBc']  
X:1
L:1/8
M:4/4
K:G
|: E E AAA z | BcBc edc | BGG dGG | BcB AGE | E AAA z | BcBc a z | ge dcBcd | e3/2 A/ z :|  