Compose a piece using the alphabetic notation of the assigned musical structure and the provided melodic motif.
X:1
L:1/8
Q:1/4=120
M:3/4
K:Bb
['G2 B2', 'G2 B2']  
X:1
L:1/8
Q:1/4=120
M:3/4
K:Bb
"^Slow and plaintive." F>G | B2 g2 (f>F) | G2 B2 (B>F) | G2 B2 (B>F) | G2 B2 (f>=e) | f2 g2 (fe) | 
 d2 g2({d} f>e) | d2 (f>d) c2 |{Bc} B4 :: d>c | B4({Bc} d>F) | G2 B2 g>f |{d} f4 f>c | 
 d2 f2({ga} b>a) | g2 (f>d) (B>F) | G2 B2 d>c | d2 f>d c2 |{Bc} B4 :|  