Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:3/4
K:C
['dc Ac BG BA FA G2 FG', 'c2 BA Bc']  
X:1
L:1/8
M:3/4
K:C
 dc Ac | BG BA FA | G2 FG AB | c2 BA Bc | d2 dc Ac | BG BA FA | G2 FG AB | c2 Ac AF |1 G2 :|2 G6 || 
 d3 e d2 | c2 BA Bc | d2 de dB | c2 BA Bc | d3 e d2 | c2 BA Bc | de dc Ad |1 G6 :|2 G2 ||  