Appointments for Alsace Tastings

[Francey]

Going to Alsace France wine region. Anyone been before that could answer some questions? i.e. heard you have to set up appointments for tastings, unlike Napa/Sonoma where you just "stop in" Don't want to be disappointed by getting there and we can't do tastings because we didn't set up appointments. Any advise or words of wisdom on where to go in that region, etc. is greatly appreciated! Thanks