Formulate a musical piece by utilizing the specified motif and alphabet-based structure.
X:1
L:1/8
Q:1/8=200
M:2/2
K:G
['BGGc BGdG', 'gage dBGB']  
X:1
L:1/8
Q:1/8=200
M:2/2
K:G
 c | BGGc BGdG | BGGc Bdge | BGGc BGdG | cAAB cdef :| gage dBGB | gage dfaf | gage dBGB | 
 cAAB cdef | gage dBGB | gage dfaf | gbeg dgBg | cAAB cdef |]  