Create a musical composition based on the alphabetic representation of the predetermined pattern and the given melodic theme.
X:1
L:1/8
M:4/4
K:G
['BGBd BGBd gfge dBGB ecdB cABG', 'dgBg dgBg dgba gfed', 'ecgc egce']  
X:1
L:1/8
M:4/4
K:G
 d>c | BGBd BGBd | gfge dBGB | ecdB cABG | E2 A2 A2 dc | BGBd BGBd | gfge dBGB | ecdB cABG | 
 D2 G2 G2 :: g2 | dgBg dgBg | dgba gfed | ea^ca ea^ca | e2 ag fed^c | dgBg dgBg | dgba gfed | 
 faba gfef | g2 g2 g2 :: B>c | dBgB dgBg | ecgc egce | dBgB dgBd | AGFE D2 Bc | dBgB dgBd | 
 ecgc egce | dBGB cAFA | G2 B2 G2 :|  