Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:4/4
K:F
['c2 (AB) cfef cBAB c2 A2', '(AB) cAfA cAAB cAfA c2 (BA)']  
X:1
L:1/8
M:4/4
K:F
 c2 (AB) cfef | cBAB c2 A2 | d2 (Bc) dgga | bagf edc=B | c2 (AB) cfef | cBAB c2 A2 | dgga bagf | 
 ecde f2 || (AB) | cAfA cAAB | cAfA c2 (BA) | dBgB dBBc | dBgB d2 (AB) | cAfA cAAB | cAfA c2 (BA) | 
 dgga bagf | ecde f2 a2 ||  