Lane,
I think there is a lot of unnecessary concentration on MIDI here, and what you want is to input NOTATION to a program, and let IT worry about the MIDI side of things.

As to which notation? I have found abc very quick and easy to input. You write it with a text editor, then feed it into a suitable program (of which there are many, including mine) for conversion to MIDI.

an abc file is VERY easy to understand and create

it just looks like a bit like this:
(a few header commands followed by lines of notes)

X:1
T: tune title
M:4/4
K:G
L:1/4

g b b g | a c c a | g b b g | c/2 c/2 a a z |

That is 4 bars of music written, and can be converted to MIDI.
You can find 1000's of examples on the net.

Later on, if you want to add MIDI effects, you can load it into a sequencer program.