Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
M:12/8
K:E
['g f2', 'B2 e']  
X:1
L:1/8
M:12/8
K:E
 B2 c efg b2 g f2 a | g2 f e2 g f2 e c2 e | B2 c efg b2 g f2 a | gfe fec e2 e edc | 
 B2 c efg b2 g f2 a | g2 f e2 g f2 e c2 e | B2 c efg b2 g f2 a | gfe fec e3 ede || 
 f2 B b2 a gfe B2 e | c2 e B2 e A2 e G2 e | f2 B b2 a gfe B2 e | cBG B2 G EGB efg | 
 f2 B b2 a gfe B2 e | c2 e B2 e A2 e G2 e | f2 B b2 a gfe B2 e | c2 e fed e3 c3 ||  