Linking instruments

See: https://musescore.org/en/node/345859 (with template attached)

Hmm, cadiz's link describes how to add a Mandolin to a score, but not how to link a standard notation staff to a tablature staff. So, try this:

As that link described add a Mandolin to a staff: either to a new, blank score or as a new staff added to an existing score. I recommend adding the "Mandolin" and the rest of these instructions will assume that you have done so. You can add the "Mandolin (tablature)" instead and simply reverse any instruction that refers to that.

Go to the Instruments tab (upper left, orange highlight; if you have 4.5.*, it's called "Layout"). Find the "Mandolin" entry and click the small triangle to its left to expand the information about this staff. The "Mandolin" will show a "Treble clef" (yellow highlight) and a button to Add staff. Click the gear button to the right of "Treble clef" (also, yellow highlight). Now, click the button to Create linked staff (green highlight).

Now the "Mandolin" entry shows two staves: the same "Treble clef" that was there before and now it also shows "[LINK] Treble clef".

Most commonly, I see standard notation above tab notation when both are included, but that's strictly your choice. Click the gear next to the one you want to be the tab staff (blue highlight) since we have a standard notation staff already. Change the Staff type (at the top) from "Standard" to one of the "Tab" types (yellow highlight).

I would recommend experimenting with all three to see which you like. Personally, I prefer the "full" type. To each their own!

Hope that helps! Good luck!