Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
Q:1/4=150
M:2/4
K:C
['Gc Bc de df ed cd/e/ |1', 'df ed cd/e/ |1 dc BG :|2']  
X:1
L:1/8
Q:1/4=150
M:2/4
K:C
 Gc Bc | de df | ed cd/e/ |1 dc BG :|2 dB c2 |: ce g>a | gf df | ed cd/e/ |1 dc BG :|2 dB c2 ||  