The organ has always been a vehicle for truly cosmic ideas - for atheists and believers alike. Acclaimed Latvian organist Iveta Apkalna explores the idea that the instrument is simply a vehicle for Christian worship digging deeper into how the organ conveys ideas of the infinite and the microscopic, the existential and the personal, of celebration, grief and joy.

Presenter: Iveta Apkalna
Producer: Steven Rajam
An Overcoat Media production for BBC World Service

(Photo: Pipe organ by Nikolaus Moll in the Innsbruck Cathedral, also known as the Cathedral of St. James in Innsbruck, Austria. Credit: Getty Images)