Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:2/2
K:F
['A2 cA B2 G2', 'FAcf a3 (a b2) b(g e2) eg']  
X:1
L:1/8
M:2/2
K:F
 c2 cf (ag)fd | c2 (cf) A2 cA | B2 G2 e2 de | f2 (ed) cBAG | FAcf agfd | c2 cf A2 cA | B2 G2 ecde | 
 f2 f2 f2 z2 :: B2 Bc dcBG | FAcf a3 (a | b2) b(g e2) eg | (gf)fa c3 A | B2 Bc (dc)BG | 
 FAcf a3 (a | b2) b(g e2) eg | g2 f2 f2 z2 :|  