FlowComposer is an AI tool based on machine learning: an intelligent assistant able to help you composing new songs in any style, automatically or interactively. 

Re-harmonization

FlowComposer allows to create a leadsheet (music score) with new harmonizations in a specific style.
Listen to the Re-harmonization examples.

Variation

With FlowComposer it is possible to create variation of a given melody.
Listen to to the Variation examples

Rendering

Given a leadsheet, it is possible to render it as audio, as if a musician was playing it, with different instruments.

Listen to the Rendering examples 

References:

1. A. Papadopoulos, P. Roy and F. Pachet. Assisted Lead Sheet Composition using FlowComposer. Proceedings of the 22nd International Conference on Principles and Practice of Constraint Programming – CP 2016, Toulouse, France (read and listen to the examples)
2. Pachet, F. and Roy, P. Imitative Leadsheet Generation with User Constraints. 21st European Conference on Artificial Intelligence (ECAI 2014), pages 1077-1078, Prague (Czech Republic), August 2014