Compose a musical piece using the designated musical pattern's alphabetic representation and the assigned melodic theme.
X:1
L:1/4
M:4/4
K:G
['B A']  
X:1
L:1/4
M:4/4
K:G
 G/A/ | B B B/A/ A | B A G2 | A c B A | G F E F | G F E3/2 B/ | B2 A/B/ c | B2 z |]  