Craft a musical piece that integrates the provided melodic theme and the corresponding alphabetical pattern.
X:1
L:1/8
M:6/8
K:Bb
['F B2 A(GF) D C3 z2']  
X:1
L:1/8
M:6/8
K:Bb
 (F2 D) | B,2 B, B,2 D | F2 F D2 B, | C2 C B,2 A, | B,3 z2 B | c2 c(FA) c | B3/2 B3/2(B,D) F | 
 B2 A(GF) D | C3 z2 B | c2 c(FA) c | B2 B(B,D) F | B2 A(GF) D | C3 z2 B,/B,/ | B,2 D FFd | 
 B B3 z D | (FE) C B,2 A, | B,3 ||  