Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
M:6/8
K:D
['aga f2 d (d^c)d', 'g2 f']  
X:1
L:1/8
M:6/8
K:D
 f | (g^g)a aga | f2 d (d^c)d | e2 e efg | b2 a afg | (a^g)a aga | f2 d (d^c)d | egf edc | d3 d2 || 
 A, | DD/D/D DA,D | FF/F/F FDF | AA/A/A AFD | B,DE A,2 c/e/ | e3 efg | b3 bge | d3 cBc | e3 d2 | 
 f | b3 bd'b | _d'3 d'c'b | d'c'b d'c'b | ^abc'{g} f3 | g2 f b2 f | g2 f b2 f | g2 f e2 d | 
 ^cdB A2 ||  