How do you tag seating at an outdoor amphitheater facility?
Hi the tags used for benches (amenity=bench) can be used on ways as well as nodes, therefore you can have a long (straight or curved) seat. Unfortunately only a single node bench/seat usually gets rendered.
Please see :- https://wiki.openstreetmap.org/wiki/Tag:amenity%3Dbench
If you goto this link and open it in JOSM you can see how I mapped seating around a local bandstand :- http://osm.org/go/0ET5NOJk6?layers=N