Create music using the given musical theme and adhere to the outlined letter-based structure.
X:1
L:1/8
M:4/4
K:Amix
['BA B2', 'AAAa ge', 'cA B2', 'ge d2']  
X:1
L:1/8
M:4/4
K:Amix
 eAAA BA B2 | AAAa gefd | eAAA BA B2 | GGGd BcdB | eAAA BA B2 | AAAa gefd | efed BA B2 | 
 GGGd BcdB || AAAa ge a2 | AAAa gefd | AAAa ge g2 | GGGd BcdB | AAAa ge a2 | AAAa gefd | 
 efga ge g2 | GGGd BcdB || cAAd cA B2 | AAAa gefd | e2 Ad cA B2 | GGGd BcdB | ceAd cA B2 | 
 AAAa gefd | efed BA B2 | GGGd BcdB || efga ge d2 | efge agfd | efga ge d2 | GGGd BcdB | 
 efga ge d2 | efge agfd | agfa ge d2 | GGGd BcdB ||  