Compose a piece using the specified musical pattern based on the alphabet and the provided melodic theme.
X:1
L:1/4
M:3/4
K:F
['G A']  
X:1
L:1/4
M:3/4
K:F
 A | A G F | c2 A | F G A | F3 | c3 | A3 | c3 | A3 | F G A | c B A | F2 E | F2 c | c2 B | A2 d | 
 c B A | G2 c | G A B | c2 F | F2 E | F2 B | B A G | A B c | A2 G | F2 |]  