Jesusita en Chihuahua (cactus polka) and Lazzarella (as a samba) in this video are played during a practice session on the 4/34 Fisher Wurlitzer, Detroit, MI in 2009. These songs show some of the speed of 1920's and 1930's Wurlitzer relays. The original relays are very fast responding and can be fixed if they break. Modern computer based relays are more difficult to fix and the computers and operating systems can die too.
Neil Jensen's 3/35 hauptwerk virtual theatre organ is used to demonstrate pizzicato. I didn't have any simple recordings of pizz done on a real Wurlitzer available for this video. Virtual organs are great for trying things at home and sound really good too, but not as super as a real theatre organ.