Craft a musical piece that integrates the provided melodic theme and the corresponding alphabetical pattern.
X:1
L:1/8
M:4/4
K:C
['BEA Dec |[M:2/2][K:G]SOSOO .!fermata!PMTCOMGA B2({c}', 'B2({c} BA) BGEF', '(GA) Bdef', '(eg) f2 (df) edBA']  
X:1
L:1/8
M:4/4
K:C
 BEA Dec |[M:2/2][K:G]SOSOO .!fermata!PMTCOMGA |: B2({c} BA) BGEF | G2 (Bd) efgd | 
 B2({c} BA) BGEF | GBAF (G2 G)A | B2({c} BA) BGEF | GABd efgd | B2({c} BA) BGEF | GBAF G2 || 
 (GA) || Bdef g2 (eg) | f2 (df) edBA | Bdef gfgb | afdf e2 (ed) | Bdef g2 (eg) | f2 (df) edBA | 
 B2 d2 d2 (ef) | gfaf gedc |]  