PlayerMachine for WIJAM - a social music improvisation platform. It is implemented on the iOS platform back in 2012.
This is part of the Chapter 4 of my PhD thesis
For more information on WIJAM, please check out this paper:
Deng, J. Q., Lau, F. C. M., Ng, H. C., Kwok, Y. K., Chen, H. K., & Liu, Y. H. (2014). WIJAM: A Mobile Collaborative Improvisation Platform under Master-Players Paradigm. In Proceedings of the 2014 International Conference on New Interfaces for Musical Expression, London, UK.
Here you could find a demo of WIJAM.