Compose a musical piece in accordance with the outlined theme and structure.
X:1
L:1/8
M:2/4
K:G
['GB d2 e2 d2 Bd cB', 'GB GB'  
X:1
L:1/8
M:2/4
K:G
 GB | d2 e2 | d2 Bd | cB Ac | BA GB | d2 e2 | d2 Bd | cB AB | G2 :| GB | GB GB | A2 Ac | Ac Ac | 
 B2 GB | GB GB | A2 FA | FA FA | G2 :|  