Make a melody from the pitches. Make sure that you don't change the orders of the pitches, as changing the order of the pitches defeats the purpose creating the matrix.
Recall that the pitches generated in step 5 were as follows:
A G D# B Bb C D Db Gb E F Ab
Bb C# D C F E Gb Ab G Eb B A
I have completed our example by writing music from these pitches.
Pick your time signature, rhythms, and dynamics in any way you like. Note that using a key signature is not necessary because your melodies were not derived with any sense of key or tonality. 20th Century composers are known for writing specific dynamic, articulation, and tempo markings, so you can imitate this style by specifically spelling out these factors as well. I have done this in the example below.
Your finished melodies will be atonal and consistent with the methodologies employed by Arnold Schoenberg and other 20th Century composers.