Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:3/4
K:G
['D2 E G3 A2 B4 d2 ef', 'd3 e']  
X:1
L:1/8
M:3/4
K:G
 D2 | E G3 A2 | B4 d2 | ef g2 (AB) | A4 b/a/g/f/ | g4 GA | B2 BA (3Bcd | B2 AG GA | G4 :| gf | 
 e2 e2 gf | e2 e2 gf | ed ef g>f | e2 ed B2 | d3 e d2 | d3 e f2 | g2 fe dc | B2 AB G2 | c2 B2 c2 | 
 d3 e f2 | gf ed c (A | B) A3 b/a/g/f/ | g4 GA | B2 BA (3Bcd | B2 AG GA | G4 :|  