Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:3/4
K:G
['G>[FA] [BG]>[Ac] [Bd]>[ce] T[Bd]2 [bd]>f [dB]2 T[Ac]2', '(eg) g3 a Tg2 f>e f2']  
X:1
L:1/8
M:3/4
K:G
"^A""G" G>[FA] [BG]>[Ac] [Bd]>[ce] | T[Bd]2 [bd]>f [dB]2 |"D7" T[Ac]2 [ac]>f [Ac]2 | 
"G" B2 [db]>g B2 | G>[FA] [BG]>[Ac] [Bd]>[ce] | T[Bd]2 [bd]>f [dB]2 |"D7" T[Ac]2 [ac]>f d>f | 
"G" g2 g2 z2 ::[K:D]"^B""Em" e2 e>f g>a |"B7" b4 b2 |"Em" b2 b>c' b>a |"D7" c'b a4 | d2 d>e f>g | 
 a4 d'2 | c'>b a>g fe | d2 d2"_>Teil A" z2 ::[K:C]"^C""C" (eg) g3 a |"Dm" Tg2 f>e f2 | 
"G7" (Gf) f3 g |"C" Tf2 e>d e2 | (eg) g3 a |"Dm" Tg2 f>e f2 |"G7" (eg) g2 a>b |"C" c'2 c'2 z2 :: 
"^D""G7" gG f2 e>d |"C" Td2 c>B c2 |"G7" (GB) dg bd' |"C" (c'b) (c'e') g2 |"G7" gG f2 e>d | 
"C" Td2 c>B c2 |"G7" GB dg c'd' |"C" c'2 c'2"_Fine" z2 :|  