Develop a musical composition based on the provided pattern of letters and incorporating the given motif within it.
X:1
L:1/8
M:4/4
K:G
['G2 GG', 'd2 dd']  
X:1
L:1/8
M:4/4
K:G
|: D2 | G2 GG GBAc | B2 BB Bdce | dgfe dcBA | G2 GG G2 dB | G2 GG GBAc | B2 BB Bece | dgfe dcBA | 
 G2 G>G G2 :: Bc | d2 dd dgfe | d2 dd d2 Bc | dBGB dBGB | cAFA cAFA | BGEG BGEG | A2 AA AcBA | 
 G2 GG GBAc | B2 BB Bdce | dgfe dcBA | G2 GG G2 :|  