Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
Q:1/4=120
M:4/4
K:G
['D2 G3 A B2 AG F>GAB c2', 'D2 (3(DEF) G3 A B2 (AG) F>GAB', 'G2 (Bc) (dc)de =f2 ef dggf g2', 'F2 (3(DEF) G3 A B2 (AG) F>GAB']  
X:1
L:1/8
Q:1/4=120
M:4/4
K:G
"^Moderate" D2 | G3 A B2 AG | F>GAB c2 Bc | d>e=fe dcA^F | G3 F D2 || (3(DEF) | G3 A B2 (AG) | 
 F>GAB c2 Bc | d>e=fd cA^FA | G4 G2 |] | (Bc) | (dc)de =f2 ef | dggf g2 de | =f2 ag fedB | 
{d} cBAG F2 || (3(DEF) | G3 A B2 (AG) | F>GAB c2 Bc | d>e=fd cA^FA | G4 G2 |]  