Construct a musical work that combines the specified alphabet-based pattern with the given melodic theme.
X:1
L:1/8
M:4/4
K:G
['BG AF', 'af gf ed']  
X:1
L:1/8
M:4/4
K:G
 D | G2 GF GA Bc | dB ge dB Ac | BE ED EF GA |1 BG AF GF ED :|2 BG AF G3 :: A | Be ed e3 f | 
 ge af gf ed |1 Bd d^c d3 e | f2 af gf ed :|2 BE ED EF GA | BG AF G3 :|  