Compose a piece of music using the specified letter-based musical form and incorporating the assigned motif.
X:1
L:1/8
M:6/8
K:C
['GAB c3 Bcd e3 def gdf |1', 'a6 agf efe dcB ABc d2 d']  
X:1
L:1/8
M:6/8
K:C
|: GAB c3 | Bcd e3 | def gdf |1 eBd c{dc}BA :|2 eBd c2 z |: e2 e ^g2 g | a6 | agf efe | dcB ABc | 
 d2 d ^f2 f | g6 | gfe dgB | d3{ed} c2 z |]  