Genie--

You can only enter music to the any above mentioned notation programs with a MIDI instrument--

Again, the best thing to do is to write your arrangements as MIDI files(in a full fledged sequencing program--I used Opcode EZVision for years) then import the Standard MIDI files into your notation program-

There are many reasons for doing this, not the least of which is that you can write and playback many parts at the same time--

Also, it is important to note that the notation programs will not allow you to edit files in created in any of the other programs so you have to edit and revise a score in the same program you wrote it-- in--This means that you can't ever let go of a program once you
ve started using it, and you are pretty much obliged to pay for their upgrades or do your work on a computer with an old operating system if you don't want to redo your arrangements from scratch when you want new copies down the road(Doing most of your work in MIDI makes it easier to deal with this problem)--

Also, if the company that created your notation program goes under(as Opcode, who created Overture) you are in the woods by yourself--