Construct a melodic piece using the alphabet-based musical sequence and the given motif.
X:1
L:1/8
M:2/2
K:G
['BcdB cBAB', 'eA A2', 'BDAD B2', 'BcdB c2 AB cdef g2 fg ecAG']  
X:1
L:1/8
M:2/2
K:G
 B3 A BcdB | cBAB cdec | d2 dc dcAG | (3FED AD BDAF | DBBA BcdB | cBAB cdef | g2 fg ecAG |1 
 FGAF G2 GA :|2 FGAF GABd |: g2 gf gdBd | g2 fg eA A2 | eA A2 eA A2 | fgaf gfef | g2 gf gdBd | 
 g2 fg eA A2 | eA A2 eA A2 |1 fgaf gdef :|2 fgaf gedc ||"^variations of 1st part" |: B3 A BcdB | 
 c2 AB cded | Addc d2 BA | D2 AD BDAD | B2 BA BcdB | c2 AB cdef | g2 fg ecAG |1 FGAF G2 GA :|2 
 FGAF GABd ||  