An AI Composer.
AIVA.ai - Aiva attempts to be a composer's tool with an easy to use interface and the ability to not only specify genres but also to upload your own custom midi files for influence. They have collaborated on many projects where live musicians performed the music. While the music curated with the tool’s and the live performances appear promising, the music you might generate in the tool is less glamorous and requires some human attention before the output is reliable.
Musenet – OpenAI’s application of the GPT-2 model to music generation. The model’s outputs were learned with little human assistance needed for curating outputs. As such, the output is based on a number of tokens, not measures, and doesn’t always musically make sense. However, particularly with piano and in the styles of classical composers, Musenet can write music surprisingly well and with greater efficiency than most others.