A Musical and Mechanical Study of Tracker Actions

The bar and slider windchest has existed in its current form for several centuries and is clearly a very effective type of action for a number of reasons. Whether mechanical organ actions allow organists to control the way in which they move the key and thus influence the transients has been discussed over recent decades and this has often given as their main advantage. However, some physical characteristics of mechanical actions, notably pluck, make it difficult for the player to control the key movement and thus vary the transients. This project investigates how the movement of the pallet actually follows the movement of the key and also summarises earlier work on how organists use rhythm and timing to play expressively. The work is now further supported by high speed photography of the key and pallet moving simultaneously. It also discusses other factors that might lead to perceived or actual transient variation.