Compose a musical piece in accordance with the outlined theme and structure.
X:1
L:1/4
M:3/1
K:D
['G4 G4']  
X:1
L:1/4
M:3/1
K:D
 D4 | G4 G4 G4 | G4 A4 B4 | =c8 c4 | =c4 c4 c4 | d8 =c4 | B4 A8 | G8 G4 | G4 G6 D2 | z8 |]  