Construct a musical work using the letter-based representation of the specified pattern and the given melodic subject.
X:1
L:1/8
Q:1/4=90
M:12/8
K:Bb
['G3 F3']  
X:1
L:1/8
Q:1/4=90
M:12/8
K:Bb
"Bb" B3 BAG G3 F3 |"F7" E3 EGF"Bb" D3 z3 | B3 BAG G3 F3 |"C7" =E3 EFG"F" F3 z3 |"F7" A3 ABc c3 F3 | 
"Bb" F3 FBc d3 z3 |"D7" d3 dcA"Gm" B3"Eb" G3 |"Bb/F" F3"F7" FFF"Bb" F3 z3 |]  