Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
M:2/2
K:G
['dG G2 dgfg d3 e', 'dg g2', 'cFdF cF', 'dg g2', 'bgag fdde fdeg |1 fdcA BG :|2']  
X:1
L:1/8
M:2/2
K:G
 Bc | dG G2 dgfg | d3 e dcAB | cF F2 cF F2 | cded cABc | dG G2 dgfg | d3 e dcAG | FGAB cded |1 
 fdcA G2 :|2 fdcA BG |: Bc | dg g2 fagf | dg g2 bgaf | d^cde f2{a} fe | defg afge | dg g2 fagf | 
 dg g2 bgag | fdde fdeg |1 fdcA BG :|2 fdcA G2 ||"^Variation of the first part" |: Bc | 
 dG G2 dGeG | dG G2 dcAB | cF F2 cFdF | cF F2 cABc | dG G2 dGeG | dG G2 dcAG | FGAB cded |1 
 fdcA G2 :|2 fdcA BG |: Bc | dg g2 fagf | dg g2 bgaf | d^cde f2{a} fe | defg afge | dg g2 fagf | 
 dg g2 bgag | fdde fdeg |1 fdcA BG :|2 fdcA G2 ||  