Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
Q:1/2=60
M:2/2
K:D
['B (AF)(FE) FDDB (AF)(FE) F2 FB (AF)(FE)', 'e/d/c/B/ Ad']  
X:1
L:1/8
Q:1/2=60
M:2/2
K:D
 B | (AF)(FE) FDDB | (AF)(FE) F2 FB | (AF)(FE) FDDE | FDAF D/D/D D :| B | dedB e/d/c/B/ Ad | 
 (AF)(FE) E2 EB | d>edB e/d/c/B/ Ad | FDAF D2 DB | d>edB e/d/c/B/ Ad | GFFE E2 Ed | 
 BGAF GE (F/G/)A | FDAF D/D/D D |]  