The problem was here
(defn get-events
[xz]
(map (juxt
#(zf/xml1-> % :title zf/text)
#(zf/xml1-> % :performers :performer :name zf/text)
#(zf/xml1-> % :start_time zf/text)
#(zf/xml1-> % :stop_time zf/text))
(zf/xml-> xz :events :event)))
I've put :title zf/text in parenthesis, and that was a mistake. Now it works just fine.