This may be the wrong forum.
I want to be able to type E-D-C-D-E-E-E into my computer and hear the first line of “Mary had a little lamb.”
Does anyone know of some software that would let me do that?
I know of two that lets you do something similar but I believe they’ve gone out of print. That would be MusicTime and it sequel Music@Passport. Both are, or were, from Passport Designs. MusicTime has since been licensed by GVOX and costs $120.
Finale Notepad is one (fairly complex) free music-notation program, and there’s more listed here. If you want something simpler, then music education software is the place to look - there’s plenty of free stuff around, eg. here.