Develop a musical composition based on the provided pattern of letters and incorporating the given motif within it.
X:1
L:1/8
M:2/2
K:G
['BGGB d2 (cB)', 'g2 d2 gfdB GBdB Aaag fedc Bdgf']  
X:1
L:1/8
M:2/2
K:G
 (dc) | BGGB d2 (cB) | ADDE FGAc | BGGB d2 (cB) | cdeg fdcA | BGGB d2 (cB) | ADDE FGAc | 
 BGGB d2 (cB) | cdef g2 || d2 | gfdB GBdB | Aaag fedc | Bdgf edcB | cdef g2 dB | G2 gf edcB | 
 ADDE F2 GA | BGGB cAAg | fdef g2 |]  