Develop a musical composition utilizing the presented motif and adhering to the required structure.
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
['DGBG dGBG', 'gbag f2 fe fgaf', 'bgag fdcA BGGg bgdg bgdg afdf agfa'  
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
 F | DGBG dGBG | DFAF cFAF | DGBG dGBG | BdcA BGGF |"^5" DGBG dGBG | DFAF cFAF | GABc d2 ge | 
 fdcA BGG || f |"^9" g2 gf gbag | f2 fe fgaf | g2 gf gbag | fdcA BGGf |"^13" g2 gf gbag | 
 f2 fe fgaf | gfga b2 ag | fdcA BGG || g |"^17" bgdg bagb | afdf agfa | bgdg bgag | fdcA BGGg | 
"^21" bgdg bgdg | afdf agfa | bgaf (3gfe dB | cedc BGG |]  