Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:6/8
K:D
['DDD DBG', 'GEC dcd DdB AGF dcd dfa gfe']  
X:1
L:1/8
M:6/8
K:D
 DDD DBG | FAF DDD | DBG Acd | DDD DBG | FAF GEG | =c(A/B/c/A/) GEC :: dcd DdB | AGF dcd | 
 dfa gfe | gdg edc | dcB AGF | =c(A/B/c/A) GEC :|  