I don't think so....................
I have REASON and my understanding is that you need a sound module to create sounds within REASON unless you are just using the drum machine..........
But let me tell you, "REASON is da BOMB"................................
Check out this little program. Uses your keyboard as an...uh...keyboard. 2 octaves useing the lower and upper 2 rows of keys.
No velocity sensativity, of course, but good enough to get some ideas down.
It needs to be used with a midi loopback device to route the MIDI back into the computer. I use MIDI Yoke found at http://www.midiox.com/ (You'll have to poke around a little to find it- wouldn't let me link direct to the site.)