Compose a piece of music using the specified alphabetical notation system and the provided theme.
X:1
L:1/8
Q:1/2=75
M:4/4
K:Bb
['B d>BF>B d>BA>c', 'B2 B2']  
X:1
L:1/8
Q:1/2=75
M:4/4
K:Bb
|: B | d>BF>B d>BA>c | B>dc>e d3 c | B>AG>F E>DC>c | A2 F2 F2 z B | d>BF>B d>BA>c | B>df>b g3 f | 
 e>dc>B G>ec>A | B2 B2 B2 z :: f | d>fB>d F>BD>F | G>FE>c C3 B, | A,>CF>E D>FB>F |{G} F2 ED C3 F | 
 G>FEc A>GFd | B>AGd e3 g | fF GA B>dc>A | B2 B2 B2 z :|  