Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
Q:1/8=1
M:4/4
K:Amin
['B2 B2', '.A2 AG D.A,']  
X:1
L:1/8
Q:1/8=1
M:4/4
K:Amin
"Am" z A2 B c2 c2 | c2 B2 c4 | _e e2 e_e cB A |"E" B2 B2 e4 | z ^G2 A B2 B2 | B2 B2 B4 | 
 e e2 e_e cB ^G |1"Am" A6 z2 :|2"Am" A6 (3cd_e |:[K:A]{f}"A" e2 a2 c3 c |"E7" B dc B"A" A B=c c | 
{f} e2 a2 c3 c |"E7" B dc B"A" A4 ::[K:Dmin]"Dm" A4 F3 E | E D3 z D FA |"Gm" d4 B3 A | 
 A G3 z G AB |"A" A2 E2 A3 G |"Dm" G F3 z F ED |"A" .A2 .A2"A7" .A2 .A2 | AG FE"Dm" D.A, .D.F :|  