Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/4
M:4/4
K:C
['c c', 'c c', 'G G', '[BG]2 [cA] [BG] [AF]2 [BG] [BG] [cA]']  
X:1
L:1/4
M:4/4
K:C
|: C2 E2 | G2 z3/4 G/<A/B/4 | c/>B/A/>G/ F/>E/D/>C/ | G G/>G/ G e/>d/ | c c c f/>e/ | d d d g/>f/ | 
 e e d/>c/d/>e/ | c c c z :: g g a/g/f/e/ | d2 g2 | c B A d | G G/>G/ G e/>d/ | c c c f/>e/ | 
 d d d g/>f/ | e e d/>c/d/>e/ | c c c z ::[K:G] d d/c/ B B | d c A d/B/ | G G A/G/F/G/ | 
 ^G A z G/4A/4B/4c/4 | d d/c/ B B | d c A d | g d/>B/ A/>G/A/>B/ | G G G z :: 
 !fermata![AF]2 [BG]2 | [cA] [BG] [AF]2 | [BG] [BG] [cA] [cA] | [BG]2 [AF]2{GABc} | [dB]2 [cA]2 | 
 [BG]2 A/B/c/A/ | [GB,]2 [FC]2 | [GB,] [GB,] [GB,]"^da Capo" z :|  