Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
Q:1/4=100
M:9/8
K:B
['G6 GEG F3 D2 C B,3- B,2']  
X:1
L:1/8
Q:1/4=100
M:9/8
K:B
 B,DG |"B" F3 D3 DCB, |"F#" D3 C3 C^B,C |"F#7" E3 G3 GFE |"B" E3 D3 B,DF | B3 F3 FED |"E" G6 GEG | 
"B/F#" F3 D3"F#7" D2 C |"B" B,3- B,2 z ||"F#7" FGA |"B" B3 B3 BAG | G3 F3"F#7" FGA | 
"B" B3 B3"C#" BAG |"F#" G3 F3 B,DG |"B" F3 D3 DCB, |"E" G6 GEG |"B/F#" F3 D3"F#7" D2 C | 
"B" B,3- B,2 z |]  