Construct a musical piece utilizing the given sequence in alphabetical form and the supplied motif.
X:1
L:1/8
M:2/2
K:G
['B2 (TBA)', 'Bdef g2']  
X:1
L:1/8
M:2/2
K:G
 (GA) | B2 (TBA) BGEF | GABd efed | B2 (TBA) BGEG | FGAF"^end" G2 :| (GA) | Bdef g2 (eg) | 
 Tf2 (df) edBA | Bdef g2 (fg) | agfg e2 z2 | Bdef g2 (eg) | Tf2 (df) edBA | Bdd^c d2 (ef) | 
 geaf{a} gfed |]  