Hello Eamoon,

I looked at a picture of the back side of your Kurzweil SP 76 Stage Piano. It has a pair of MIDI In and Out connectors, not USB. You need the following configuration:

1. A pair of MIDI cables that go from the MIDI In and Out connectors of your Kurzweil to #2.
2. A MIDI/USB hub, to which you will connect the two MIDI cables. I highly recommend the Midisport 1x1, for about $40.
3. A USB cable that runs from the MIDI/USB hub to your computer. (I don't know whether the Midisport 1x1 comes with a USB cable. If not, they're inexpensive.)

Note, Notation Composer is a MIDI sequencer, as well as a notation editor. It records the "sequence of MIDI" notes from your MIDI (Kurweil) keyboard.

Cheers
-- Mark