Enter tab and ask to see the standard notation or vice versa. The standard notation is correctly laid out with bar lines, sharps, flats, naturals etc. following the standard conventions (e.g. it doesn't use flats in sharp keys). The amount of function is huge - for instance you could:
For instance bass guitar
Muse generates optimised tablature , working out fingerings for the piece as a whole.
You can enter the tab either from the keyboard (probably the quickest) or using the mouse. Either way it's very easy.
By mouse you select the length of the note (e.g. click on that note in the note palette), move it over the right string and press the mouse button down. A frets menu appears, select the right fret and take the button up. Could hardly be easier.
By keyboard, you move the cursor to the right place (e.g. by using the arrow keys), press space to activate entering frets, type the fret number and press return. You select note lengths either from menus or from the notes palette or by typing the short-cuts e.g. 4 gives a quarter note ("crotchet" in UK).
All of the usual facilities of Muse (cut, copy, paste, UNDO etc) work with tablature as well as the notation so you get a really high function editor.
This level of function normally comes at a high price. Muse is priced at 20 UK pounds (currently under 35 US dollars, there are several ways to pay). This is very cheap for a music editor with this degree of function!
You get 30 days free trial anyway - so don't pay anything at all unless you like it.