Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
Q:1/4=100
M:2/2
K:D
['B ADFD ADFB ADFA E/E/E GB ADFD', 'd f defd gefd f>edf e/e/e (eB)']  
X:1
L:1/8
Q:1/4=100
M:2/2
K:D
 B | ADFD ADFB | ADFA E/E/E GB | ADFD ABde | fdef d/d/d d :: f | defd gefd | f>edf e/e/e (eB) | 
 defd eBdA | (B/A/B/c/) dF D/D/D D :|  