The concert organ is the largest in the country, and organists worldwide take pleasure in playing it and in recording in the church. Inaugurated in December 1992, it was constructed by Johannes Klais Organworks in Bonn, Germany, and has four manuals and a pedal, 72 stops and 5275 pipes. It is 15 m high and weighs 25 tonnes. The largest pipes are 10 m long.
The organ was financed substantially by private gifts – people were offered the opportunity to purchase individual pipes. There are still some left to be bought, and the shop has deeds of gift that can be bought and that certify that the purchaser is the patron of a particular pipe. At the church entrance a collection pipe can be found, for those interested in supporting the maintenance of the organ.
The Hallgrímskirkja Friends of the Arts Society regularly organizes organ concerts, especially during the summer time. The International Organ Summer, an annual festival with organ concerts, is held from June until August.
The Chancel organ
The small chancel organ, located nearest the altar, has 10 voices, and was built by Th. Frobenius & Sönner’s organ works in Lyngby, Denmark. It was inaugurated in December 1985.