1. The patterns should be .mid files and inside directory midi_in
2. Each musician has a unique ID which is represented by art_id in the code.
3. Consider the example art_id = 52, then each pattern should be named 52_0_0.mid, 52_1_0.mid, 52_2_0.mid, ...
4. create_data.py will read the data, create the synthetic variations, and dump a csv file in data/
5. sample_data.py will sample the data that was previously created, and dump the files in sampled_data/
6. Finally rnn_test_v3.py will read the sampled files, train and save the model