Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
Q:1/4=144
M:7/8
K:D
['[EC]2 [EC]2', '[BG]3 [AF]2']  
X:1
L:1/8
Q:1/4=144
M:7/8
K:D
 [DA,][CA,][DA,] [EC]2 [EC]2 | [A,F,] [EC]2 [EC]2 [EC]2 | [FD]3 [EC]2 [DB,]2 | [FD]2 [GE] [AF]4 | 
 [BG]3 [AF]2 [GE][FD] | [EC]2 [DB,] [AF]2 [GE]2 | [FD]3 [EC]2 [EC]2 | [DD,]3 z4 |: 
 [DA,]3 [FD]2 [GE]2 | [AF]3 [AF]4 | [BG]3 [AF]2 [GE]2 | [AF]7 | [BG]3 [AF]2 [GE][FD] | 
 [EC]2 [DB,] [AF]2 [GE]2 | [FD]3 [EC]2 [EC]2 | [DD,]3 [DD,]3 z :|  