Develop a musical composition based on the provided pattern of letters and incorporating the given motif within it.
X:1
L:1/8
Q:3/8=120
M:9/8
K:D
['FGA ABc d3 FGA', 'd2 d', 'B2 B BGE BGE']  
X:1
L:1/8
Q:3/8=120
M:9/8
K:D
 FGA ABc d3 | FGA ABc B3 :| d2 d ded cBA | B2 B dcB AGF | d2 d dfd edc | Bcd dcB AFD :| 
 B2 B BGE BGE | B2 B BGE BGE | B2 B BGE BGE | FGA Bcd AFD |]  