When using a midi controller, and NOT using the computer keys, Sylenth v2.21 seems to work fine. (for some reason, playing sylenth using the computer keys causes lag, etc)
This is just a demo, not finished really, but I had fun; sylenth1 continues to inspire me every time I use it!
Rob Lee's sounds are in this one in places.
enjoy
http://soundcloud.com/scott-m-oram/therona
I need to get the transitions and drums sorted