Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
Q:1/4=66
M:3/4
K:Cmix
['CD E2', 'CD E2']  
X:1
L:1/8
Q:1/4=66
M:3/4
K:Cmix
 CD | E2 E2 EF | E2 D2 EG | A2 D2 DE | E2 D2 CD | EG FE DC | D4 CD | E2 C2 CD | C4 :| CD | 
 E2 E2 EF | G2 FE DE | C2 c2 cd | d2 c2 CD | E2 E2 EF | G2 FE DE | C2 c2 cd | c4 GA | B2 B2 AG | 
 A4 C2 | D2 D2 (3CDE | E2 D2 CD | EG FE DC | D4 CD | E2 C2 CD | C4 :|  