Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:4/4
K:Gmin
['d<BB<G d<B (TBA/B/)', '(Tg^f/g/) f<dTc>B AF', 'BGG B/c/ d<GB<G DG/A/ BG c<FA<F c<FA<c', 'a>gf<c AF (Tf=e/f/)']  
X:1
L:1/8
M:4/4
K:Gmin
 B/c/ | d<BB<G d<B (TBA/B/) | A<cTc>B AFFB/c/ | d<BB<G d<B (TBA/B/) | c<fF>A B(GG)B/c/ | 
 d<BB<G d<B (TBA/B/) | A<cTc>B A(FF)B/c/ | d<BB<G G2 (Tg^f/g/) | =f<dTc>d BGG || f | 
 g>fd<c B<G (Tg^f/g/) | f<dTc>B AF (Tf=d/f/) | g>fd>c B<G (Tgf/g/) | f<dTc>d BGGf | 
 g>fd>c BG (Tg^f/g/) | f<dTc>B AF (Tf=e/f/) | gdBg fcAf | dB d/c/B/A/ BGG |: B/c/ | 
 d<GB<G DG/A/ BG | c<FA<F c<FA<c | d<GB<G D<GB,<D | CD/E/ D^F GG,G, :| d | b>ag<d B<G (Tg^f/g/) | 
{fg} a>gf<c AF (Tf=e/f/) | b>ag<d BG (Tg^f/g/) | =f<dc>d B<GGd | b>ag<d BG (g^f/g/) | 
{=fg} a>gf<c AF (Tf=e/f/) | B<Gc<A d<Be<c | dg b/a/g/^f/ g>ag |]  