Develop musical compositions by respecting the prescribed structure and combining the presented musical concept.
X:1
L:1/8
M:2/4
K:C
['dd dB cd ec', 'd2 aa af gg ge ff ed'  
X:1
L:1/8
M:2/4
K:C
 dd dB | cd ec | dd d2 :: aa af | gg ge | ff ed | cd ec | dd d2 :|  