The Dutch born organist, conductor, music pedagogue, church musician and composer, Willem Mathlener left a rich inheritance in the field of organ music in South Africa. He was born in 1909 in Delft in the Netherlands and distinguished himself as an organist and conductor in the thirties and forties of the previous century. He answered the calling of the Nederduitsch Reformed Church in South Africa to improve the standard of church music by immigrating to South Africa in 1948 at the age of 39. He settled in Vereeniging as a music teacher and organist from where he started to introduce his ideas about church music to the Nederduitsch Reformed Church and others. This led to the establishment of the Council for Church Music in 1951. Three years later the Church Music School in Krugersdorp was founded. This institution developed to such an extent that the Conservatoire for Music, Pretoria was established in 1960, the institution that Mathlener was mostly associated with. He implemented his beliefs about musical training which was the result of his own training at a European Conservatoire at both these institutions. As the secretary of the Council for Church Music he had a profound influence on the development and promotion of church music in South Africa. He assisted in the compilation of the Psalm and Hymn book of 1978 by supplying a large number of harmonisations for Hymns in this volume. As an organ advisor he designed about 200 organs. Mathlener’s talent as a composer developed naturally through his capacity as church musician and pedagogue. He composed organ music that can be used supplementary to the organist’s task as accompanist. His piano music fills the need for short study pieces for piano tuition. Since the majority of Mathlener’s compositions do not exceed 30 bars he can be considered to be a miniaturist. His choral arrangements show for the most part a diatonic tonality and a contrapuntal texture which blends in with the style of music for liturgical use. A Psalm or Hymn melody forms mainly the basis for his organ music. Mathlener’s large compositional output which comprises 223 choral harmonisations, 175 works for organ, 53 works for piano and 12 vocal works created the need for a system to arrange his compositions in an orderly fashion. Some of his compositions were published in volumes and others are single unpublished works. The catalogue attempts to arrange Mathlener’s compositions in a logical way thus forming a comprehensive picture of the oeuvre of this composer as well as providing a useful reference tool for organists and other interested people. / Dissertation (MA)--University of Pretoria, 2015. / tm2015 / Music / MA / Unrestricted