Wolfgang Köhler, professor of jazz piano at the Berlin Jazz Institute, writes music in the border area between classical, jazz and contemporary music. His'Variations' for cello and piano are cross -over music in the best sense of the word and a rewarding concert and examination piece of medium difficulty (use of thumb position demanded) . The three variations on a vocal theme use different styles like Latin (var. 1) , ballad (var. 2) to rhythm and harmony inspired by Prokofiev (var. 3) . The recapitulation of the cantabile theme concludes the original, effective piece which has a duration of six minutes.