Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:2/4
K:G
['FAce (dB) B2 d(3(d/e/d/)', 'cege (dB) B2 d(3(d/e/d/)', '(Bd) =f2', 'dcc z vA2 (c=f) a2 (gf) |{a}']  
X:1
L:1/8
M:2/4
K:G
 uG | FAce | (dB) B2 | d(3(d/e/d/) cA | GBBG | FAce | (dB) B2 | d(3(d/e/d/) cA | AGG :: uB | cege | 
 (dB) B2 | d(3(d/e/d/) cA | GBBB | cege | (dB) B2 | d(3(d/e/d/) cA | AGG :: z | vG2 (Bd) | 
 =f2 (ef) | gcBd | d/c/B/A/ G/=F/E/F/ | G2 (Bd) | =f2 (ea) | gcBd | dcc :: z | vA2 (c=f) | 
 a2 (gf) |{a} gfga | g2 (ec) | G2 (Bd) | =f2 (ea) | gcBd | dcc :|  