Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
Q:1/4=120
M:2/2
K:A
['(3efg a2 A4 c2 BAGB A2 AA', 'A2 cA e2']  
X:1
L:1/8
Q:1/4=120
M:2/2
K:A
"^Fast" (3efg | a2 A4 c2 | BAGB A2 AA | Bcde fedc | BAGA B2 (3efg | a2 A4 c2 | BAGB A2 AA | 
 Bcde fefg | abag a2 :| A2- | A2 cA e2 AA | Bcde (f/g/f) e2 | A2 cA e2 Ac | BAGF E2 FG | 
 A2 cA e2 AA | Bcde (f/g/f) e2 | agfe dcBA | GABc A2 :|  