Construct a musical work following the provided guidelines and thematic elements.
X:1
L:1/8
Q:1/8=424
M:4/4
K:Bb
['BAGB AGFD GFDG FDCF DGGF GABc']  
X:1
L:1/8
Q:1/8=424
M:4/4
K:Bb
|: BAGB AGFD | GFDG FDCF | DGGF GABc | dggg fdcA | BAGB AGFD | GFDG FDCF | DGGF GABc | 
 dBcA BG G2 :|3 dggf gddd | gbag fdd=e | f=efg fccc | fgag fd c2 | dggf gddd | gbag fdd=e | 
 f=efd gfge | a_a=ag fd c2 :|  