Jedi: If you've got a Mac, I highly recommend going with 'Digital Performer' by MOTU. http://www.motu.com/english/software/dp/body.html
It's a VERY powerful program, yet very user friendly and has the most elegant design inteface of all the midi/digital audio sequencers out there. It uses FreeMidi. I only wish Digital Performer were available on the PC-Windows platform too. Logic Audio is another powerful choice as well, but be prepared for a STEEP learning curve. http://www.emagic.de/english/products/index.html


I recently switched from Mac (Logic Audio)
to Cakewalk-Sonar http://cakewalk.com
on the PC, primarily because Cakewalk is supported by such a large arranger keyboard user base, and as a result, supports more 'arranger keyboard model' patch lists (instrument definitions) than any of its competitors. With the recent release of Cakewalk-Sonar, I feel that the PC has finally become a viable alternative to the once Mac dominated world of professional midi music production. - Scott