program online or offline that make letters to notes

[catopett]

Hi, i am looking programs that make a letter (sutch as C, and make it a note)
As in, i type "C, D" and see a note placed on sheet! in ex, "musescore"

[j_tour]

Hi, i am looking programs that make a letter (sutch as C, and make it a note)
As in, i type "C, D" and see a note placed on sheet! in ex, "musescore"

If that's all you want to do, then you just have to type in using the TeX typesetting environment.  Lilypond is probably the best known standard for engraving standard notation.  It looks good, and is not very difficult, and indeed, you just type in using a regular keyboard like you say.

Unless you're a pretty quick typist, though, you should probably just use Musescore or similar, because of the large-ish amount of boilerplate code you'd use in your text document, preferably typed in a regular text editor like vim, or whatever you want.

And you have to render the markup, to a PDF via postscript, for example (if you like), to view the results.

If it's just the interface of software like Musescore that's bugging you, I don't know of any alternatives among notation software that are any easier:  they are all pretty clumsy.  I believe the keyboard interface (computer keyboard) of Musescore allows you to just type in notes, without using a mouse or a trackpad, but I can't remember the shortcuts. 

In a more curmudgeonly mood, I'd remind you about the existence of pencils and staff paper, but the above is the extent of my knowledge.