Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/16
Q:1/2=60
M:2/4
K:G
['DEFD G2G2', 'G4 g2g2 fgaf g2g2 fga2 gfed e2e2']  
X:1
L:1/16
Q:1/2=60
M:2/4
K:G
 DEFD G2G2 | GABc d2B2 | AGFE D2EF | G2E2 E4 | DEFD G2G2 | Bc d2 g2e2 | dcBA G2A2 | B2G2 G4 :| 
 g2g2 fgaf | g2g2 fga2 | gfed e2e2 | B2d2 d4 | dcBc d2d2 | e2ef g2e2 | dcBA G2A2 | B2G2 G4 |]  