Create musical pieces following the given structure and incorporating the suggested musical concept.
X:1
L:1/8
M:4/4
K:D
['FA FA', 'Ac ef'  
X:1
L:1/8
M:4/4
K:D
 DF Ad fd fd | cd ec df dA | FA FA GB GB | FA FA EA EA | DF Ad fd fd | cd ec df dA | FA FA GB GB | 
 Ac ec d4 :: Ac ef ge ce | de fg aa fd | Ac ef gf gb | af ge fa fd | Ac ef ge ce | de fg af ge | 
 fd ec dB AG | FA Bc d4 :|  