Construct a musical composition using the provided motif and maintain the designated form.
X:1
L:1/8
Q:1/4=100
M:3/8
K:Bb
['D D2']  
X:1
L:1/8
Q:1/4=100
M:3/8
K:Bb
 F | F2 G | G2 F | F2 D | D2 E | E2 D | D2 C | C2 D | D2 C | C B, B, | B, z C | C2 D | D2 C | 
 C2 B,- | B,2 z ||  