Create a musical piece with the provided alphabetic notation system and theme.
X:1
L:1/8
M:4/4
K:Bb
['B2 Ac c2']  
X:1
L:1/8
M:4/4
K:Bb
 BF | F2 B2 cBAG | FE D2 B2 Ac | c2 B2 z2 BG | F2 B2 cBAG | FE D2 B2 Ac | c2 B2 z2 AB | 
 c2 d2 edcB | AB c2 d2 ed | cBAG F2 B2 | Ac c2 B2 |]  