(b Chicago, March 23, 1881; d Los Angeles, Aug 17, 1955). American popular pianist, teacher and editor. He studied the piano as a youth and in 1903 opened a teaching studio in Chicago with the advertisement ‘Ragtime Taught in Ten Lessons’. He simplified African-American ragtime piano playing to three essential melodic-rhythmic patterns or ‘movements’, and these became the basis for his teaching method and for a series of instruction books he brought out from 1904. Christensen’s Rag-time Instruction Book for Piano went through numerous revisions and title changes to incorporate early jazz and, eventually, swing styles; one method book remained in print until at least 1955.
Early in his career Christensen began establishing branch schools to teach ragtime piano. By 1914 he had founded 50 branches, and by 1918 he had schools in most major cities in the USA and also some abroad. By 1935 these schools had taught ragtime, popular piano and jazz piano to approximately 500,000 (mostly white) pupils....