Construct a melodic piece using the alphabet-based musical sequence and the given motif.
X:1
L:1/8
M:4/4
K:C
['B2 G GBG', 'd2 g']  
X:1
L:1/8
M:4/4
K:C
[M:6/8][K:G] .abc c | B2 G GBG | A2 B c2 e | B2 G GBG | ecA ecA | B2 G GBG | A2 B c2 e | dBd gfe | 
 dBG G2 :| | c | B2 c d2 g | ece d2 g | BGB dBG | ecA ecA | B2 c d2 g | ece d2 c | Bcd gfe | 
 dBG G2 :|  