Research->Music Software Development->Developing MIDI-Related Application->Developing Automated Composing System->What Is Sweet Melody?
This section is about my thinking toward what sweet meldoy is.
What Is Between Chaos & Order
I think that "hard to understand the method by 100% random numbers" and "method according to 100% rule is bored" were understood from explaining "Random Numbers & Music Theory" of the previous page. These are greatly related whether the following sound is predictable from the previous sound. "Good melody" is a melody "An unexpected sound might come occasionally though the expected sound often comes by the flow from the previous sound". For example, you will find the following melody boring.
This is because it completely repeat the same phrase and you can expect the next sound from the previous sound. It becomes better if unpredictable movement is added, and it becomes more like melody as follows.
Just 2 unpredictable movements were added. Still boring but considerably better than before.
Make Chaos Closer To Order = Filter
Therefore, it is good to create a melody that is between "chaos" and "order" by automated composing. I will try to bring it closer to the state of "order" by putting somthing that has restrictions looser than "order" into the world of "chaos" generated by random numbers.
For this experiment, I'd like to use a new music theory as "sound level must be within 60 to 72, and note length should be within 48 to 96."

Algorithm - Chaos
1 The following procedure is repeated until 20 sounds are generated.
2 Random numbers from 0 to 127 are generated, and consider them as sound level.
3 Random numbers from 0 to 127 are generated, and consider them as note length.

Algorithm - Order
1 The following procedure is repeated until 20 sounds are generated.
2 Sound level is 60.
3 Note length is 96.

Algorithm - Make Chaos Closer To Order
1 The following procedure is repeated until 20 sounds are generated.
2 Generate random numbers from 0 to 127.
3 If the generated value is not within 60 to 72, repeat the previous step.
If it is within 60 to 72, then use the value as sound level.
‚S Generate random numbers from 0 to 127.
3 If the generated value is not within 48 to 96, repeat the previous step.
Note numbers from 60 to 72 are located in the upper "do" sound from the center "do" sound. 48 ticks are equal to eigth note and 96 ticks are equal to quarter note.
Listen You can listen to the midi file created by the above algorithm.
If you listen to the above file, you will recognize that it is better than the previous "Chaos" or "Order" MIDI files in musical sense. It is easier to predict the next sound since the note range is more limited than the "Chaos". It is easier to predict the next sound if you are to pick the choice from 60 to 72 than from 0 to 127.
Throwing away what mismatches the music theory is called "filtering".