Construct a musical work using the letter-based representation of the specified pattern and the given melodic subject.
X:1
L:1/8
M:2/4
K:A
['ec d2', 'ec ea']  
X:1
L:1/8
M:2/4
K:A
|: f/ | ec d2 | ec d2 | B2 ed | Bc df | ef/e/ df | ec dc | Bc/B/ ed | Bc A3/2 :: f/ | ec ea | 
 gf f/g/a/e/ | f/4g/4f/e fg | fe c>d | ec ea | fd fa | gb eg | ba a3/2 :|  