Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
M:2/2
K:D
['AG F2 DF ABAG FADF A2 d2', 'dBcA BGFG', 'fddd fddd']  
X:1
L:1/8
M:2/2
K:D
"^A" AG | F2 DF ABAG | FADF A2 d2 | D3 F ABAF | GFEF G2 AG | F2 DF ABAG | FADF A2 d2 | D3 F ABAF | 
 GFEF G2 B=c ||[K:G]"^B" dBcA BGFG | Ad^cd A2 B=c | dBcA BGFG | AcBA G2 Bc | dBcA BGFG | 
 ABcd efge | dBcA BGFG | AcBA G2 ag ||[K:D]"^C" fddd fddd | fdfg abag | fddd fddd | edef g2 ag | 
 fddd fddd | fdfg abag | fddd fddd | edef g2 B=c ||  