Born 22 April 1948 in Copenhagen. Studied piano with Duke Jordan, Kjell Olson, and Herman D. Koppel, and jazz theory with George Russell. Study trips to The Gambia, West Africa, in 1983 and 1985. Active on the jazz scene since 1969, primarily in Denmark, but also in Greenland, Faroe Islands, Sweden, Norway, Finland, Germany, France, Italy, Spain, the USA, and Russia. Awarded DJBFA's composer prize in 1987, the JASA prize in 1988, Statens Kunstfonds 3-year work grant in 1993 and lifelong grant from 1998.
Kaspersen has played with such groups as Blue Sun 1969-72, Alif 1976-78, and Nada 1978-80. He has worked with Lone Kellermann and with Dan Turell during the 1970s. He has led his own groups since 1979, often under the name of Space and Rhythm Jazz: from trio, quartet, quintet, and septet to the Special Occasion Band (12 musicians) and Space and Rhythm Big Band (16 musicians). From mid-1980s, he has worked in duos with Bob Rockwell, Simon Spang-Hanssen,Pierre Dørge, Horace Parlan, and as solo pianist. Formed in 2004 a sextet w. Christina von Bulow, Jakob Dinesen and Peter Dahlgren, that plays Kaspersen