Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
M:2/4
K:D
['A ddee f>e df gg ff e2', '[ec]/[ec]/[ec]/[ec]/ ea'  
X:1
L:1/8
M:2/4
K:D
 A | ddee | f>e df | gg ff | e2 ef | ggee | a>b ag | ff ee | d2 z ::[K:A] (c/d/) | 
 [ec]/[ec]/[ec]/[ec]/ ea | [ec]/[ec]/[ec]/[ec]/ ea | edcB | A3 c/d/ | [ec]/[ec]/[ec]/[ec]/ ea | 
 [ec]/[ec]/[ec]/[ec]/ ea | edcB | A2 z ::  