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:C
['.abc ||[M:2/2][K:D]', '(3(efg) (dg)']  
X:1
L:1/8
M:4/4
K:C
 .abc ||[M:2/2][K:D] (3TBddg egdg | egdB (TBA) A2 | Bddg edgd | BdAc (TBG)G z | Bddg egdg | 
 egdB (TBA)A z | bgaf gedc | BdAc (BG) G2 | (3(efg) (dg) agbg | (3(efg) (dg) ea a2 | 
 (3(efg) dg agbg | edef ag g2 | (3(efg) (dg) agbg | (3(efg) (dg) (ea) a2 | bgaf gedc | 
 BdAc (BG) G2 |]  