Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
Q:1/8=100
M:6/8
K:D
['d3- dec', "d2 c/d/ e2 a c'2 a a2", 'b/a/ a2 f age d3 Adf (ag).g']  
X:1
L:1/8
Q:1/8=100
M:6/8
K:D
"^$" A | d3- dec | d3- dec | (a2 ^g) (a2 g) | (ba).g (ag).e | d3- dec | d3- dec | (ba).f (ag).e | 
 d2"^Fine" f d2 || c/d/ | e2 a c'2 a | a2 ^g b2 b | ba^g fed | (d3 c).A.A | ABc def | ea^g baf | 
 eac edB | B3 A ||[K:F] b/a/ | a2 f age | d3 Adf | (ag).g (gf).f | (fe).e e2 a | a2 ^c' d'2 f | 
 (ag).g bag | fag fed | a3 A/c/=B/d/^c/"^$" e/ ||  