If you have the full version of Kontakt 6 you already have this.
You'll need Kontakt 6 Player to use it, another freebie.
Might as well get Komplete Kontrol while you're there, that 's a useful plugin also with some nice free synths.
I went to get it and their servers are overloaded right now. Maybe later...
I haven't tried it yet but my experiences with Native Instruments have been good so far. I have no affiliation with them, I've bought some good plugins and use some of their free stuff as well. Cheers, Kuru