Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:3/4
K:D
["gAcAge c'ae'gfe", 'd6 d2 f2 a2 ceaefc dB^GBEd c2']  
X:1
L:1/8
M:3/4
K:D
 D2 F2 A2 | dAfdaf | d'2 a2 b2 | Tg4 f2 | gAcAge | c'ae'gfe | gAcAge | c'ae'gfe | ga A2 Tc2 | d6 :: 
 d2 f2 a2 | ceaefc | dB^GBEd | c2 Bc A2 | ceac'ae | fdbf^ge | a3 BAG | FAdfa=c | BDGBdg | 
 ^GBe^gbd | cEAcea | dfac'e'g | fAdfad' | ef A2 Tc2 | !fermata!d6 :|  