Also note that MIDI is data describing keys your pressed, knobs you turned, etc. MIDI data always 'flows' from MIDI OUT to MIDI IN. If you connect MIDI IN to MIDI IN or MIDI OUT to MIDI OUT, you won't damage anything but it won't work. At a minimum, you need to connect MIDI OUT on the USB interface to MIDI IN on the Wave, but if you also connect MIDI OUT on the Wave to MIDI IN on the USB MIDI interface using a second MIDI cable, you can use the keyboard of your Wave to play soft synths in FL Studio. If the MIDI LED on the Wave blinks when you send MIDI from FL Studio, you've got the MIDI cable(s) connected correctly. The MIDI channel you're sending on from FL Studio differs from what the Wave is listening to.You did not connect the MIDI cables correctly.I don't know FL Studio, but I your probably is probably caused by one (or both) of the following issues: