Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
M:2/4
K:G
['Bd gb', 'fg ad ga bd']  
X:1
L:1/8
M:2/4
K:G
 d | Bd gb | af df | gd Bd | ce Ac | Bd gb | Ad fa | ge d^c | d2 z :: d | fg ad | ga bd | ab c'd | 
 bc' d'd | fg ad | ga bd | c'a gf | g2 z :|  