That's the beauty of the "Perform" series by TC. The Perform VK has 1/4" line inputs for your keyboard signal. No midi needed for chord recognition.
As an added plus, the VK has an 1/8" aux in that I use with my iPad ... the unit also reads chords from this input, so even if I walk out front, or play guitar, or sax, the track feeds the chords to the harmonizer.

All this is jolly well good in theory ... I'll let you all know how it works in practice, once I take it out on a job.