Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
Q:1/4=120
M:6/8
K:D
['d d2 z/ A/ A2 z/ G/', 'd/ dAA A<AG F D3 z A', 'd2 (d/e/) fef g>(fe/d/) c A3 z', 'd(3(e/f/g/) a>gf gfe f A3 z A']  
X:1
L:1/8
Q:1/4=120
M:6/8
K:D
"^Moderate" d | d2 z/ A/ A2 z/ G/ | F D3 z A | AGF GAc | d3- d2 z/ d/ || dAA A<AG | F D3 z A | 
 AGF GAc | d3- d2 |] | (d/e/) | fef g>(fe/d/) | c A3 z f | fef g>fe | d3- d(3(e/f/g/) || a>gf gfe | 
 f A3 z A | A>GF GAc | d3- d2 |]  