Our drums are VERY unusual in that we make our own hoops. These days most (virtually ALL) drum makers are using plywood maple frames made overseas or mitred multi pieced wood frames that are 8 to 12 sided. My understanding is that a hand drum made 500+ years ago would have looked very much like ours (ok maybe not dyed. lol) but someone would have gone out, cut down a tree, split it and then bent it approximately round.
We order white ash lumber in large dimension, and then cut it into lots of different sizes (for different hoops) and steam and bend it by hand. We glue the connection with a water proof glue and then sand/router all edges. Our hoops are 98% round. Ash is a very strong wood so our hoops will not move or bend over time no matter what kind of hide is pulled over them.