Lothar Graap was born on 15 June 1933 in Schweidnitz (Lower Silesia). Graap was accepted into the Schweidnitz Conservatory in 1949, but transferred to the Görlitz Church Music School a year later. After four years of study (composition and composition: Eberhard Wenzel; organ: Horst Schneider), he passed the B examination in church music. His studies were perfected in courses with Helmut Bornefeld and Siegfried Reda.
From 1954 to 1957, Graap worked as a church musician in Niemegk (Belzig district); since then, he worked as a cantor and organist at the monastery church in Cottbus until his retirement. There he built up a cantor‘s choir that was regularly present at church services and founded an ecumenical oratorio choir. After being awarded the status of A-cantor in 1975 in recognition of his many achievements, he was appointed church music director in 1981. Having long been involved in the training of C-level church musicians, Graap took over the organ playing department at the conservatory in Cottbus in 1991. In 1998, he was awarded the City of Cottbus Medal of Honour.
In 1978, Cottbus Castle Church received a new organ from Sauer (Frankfurt an der Oder). Graap organised and performed 1025 church music vespers on and with this instrument within 20 years - a concert series that is still legendary today.
Lothar Graap created around 860 works, which have been and continue to be published by many East and, above all, West German publishers. Of these, more than 50 titles have been published by Wolfgang G. Haas-Musikverlag Köln e. K. over the past two decades.
After his retirement, Lothar Graap and his wife moved to Schöneiche near Berlin in July 1998. Ten years later, at the age of 75, he took over the direction of an ecumenical choir there on a voluntary basis for another 15 years. On 29 January 2024, Lothar Graap was awarded the Federal Cross of Merit on Ribbon of the Federal Republic of Germany in Potsdam for his work far beyond the ordinary.
In terms of composition, Lothar Graap was strongly influenced by his teacher Eberhard Wenzel and Paul Hindemith and developed his own style. His compositional work is rooted in worship and is determined by the words of the Bible. The instrumentation and forms are essentially orientated towards the practice of worship. However, his contrapuntally emphasised style of writing, dominated by a tart, expressive sound, deliberately remains within the boundaries of good general comprehensibility and moves along the lines of artistic simplicity.