Compose a piece of music following the specified structure and theme.
X:1
L:1/8
M:4/4
K:D
['fg agfe fg a2 F4', 'A4 Bc'  
X:1
L:1/8
M:4/4
K:D
 fg | agfe fg a2 | F4 GFED | F4 GFED | C2 E4 fg | agfe fg a2 | F4 F2 EF | D2 A4 Bc | d2 D4 || 
 D2 d4 ef | g2 f2 g4 | c2 e4 de | c2 A4 Bc | dcBA BcBA | G2 F2 E4 | D2 A4 Bc | d4 D4 ||  