I'm planning my wife's birthday which will be April 9th, 2020. She is interested in spending the night in a Scottish castle near the highlands or possibly Edinburgh. For her birthday party she would like to celebrate at a proper Scottish pub with local musicians playing Scottish music. Does anyone have suggestions of Castles and Pubs near the Highlands or Edinburgh?
For great Scottish "trad" music in an authentic pub, you can't beat Sandy Bell's in the middle of Edinburgh. Really excellent music (not a tourist trap). You're not going to have a "party" there (no paper hats, etc.) but it's a real pub with incredible music. A highlight of any trip to Scotland.
Can't help you with a castle to sleep in.
Scotland has lots of castles converted to hotels. Considerations for your choice will include where in Scotland (how far from Edinburgh) you want to be, price (level of luxuriousness), and whether you care about it being a "real" castle dating from medieval times (some so-called castles are really aristocratic country houses from more recent eras). Here is a pretty comprehensive list.