Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:4/4
K:D
['FG A^GAB Adfd B2 gf edcB', 'd2 cd e^def gece dcde fdAd g2']  
X:1
L:1/8
M:4/4
K:D
 FG | A^GAB Adfd | B2 gf edcB | A^GAB AFDF | E2 ED E2 FG | A^GAB Adfd | B2 gf edcB | Adfa gecd | 
 eddc d2 :: cd | e^def gece | dcde fdAd | g2 f2 e2 d2 | c2 B2 A2 FG | A^GAB Adfd | B2 gf edcB | 
 Aafd Bgec | d2 f2 d2 :|  