Jan W. Morthenson has been played on NTS shows including samb_rules, with Ultra (1970) first played on 28 February 2019.

Jan W. Morthenson (born April 7, 1940 in Örnsköldsvik, Sweden) is a prominent Swedish composer, critic, and writer primarily known for his criticism of music in Sweden and his compositional styles of non-figurative music, music that aimed to avoid any relationship to past compositional techniques, and meta-music, which alluded to historical music genres in order to criticize them. Morthenson's success as a composer and intellect in Sweden is reflected by the influential positions he has held throughout his career. He was on the board for the Electronic Music Studio from 1973-1975, he acted as chairman of the Swedish section of the International Society for Contemporary Music (ICSM) from 1974-1975, he was vice-chairman of the ISCM council from 1975-1978, and he was also the chairman for Fylkingen, a Swedish chamber music society that focuses primarily on new music, from 1975-1976.

Morthenson began studying music in Stockholm in 1956 with Runar Mangs, a prominent Swedish music critic. Mangs left a lasting impression on young Morthenson, who would later refer to him in an obituary as one of the most important contemporary music critics in Sweden.[3] Four years after Morthenson began working with Mangs, he went on to study privately with Ingvar Lindholm in 1960,[3] and premiered his first public work, Wechselspeil I (1960) for solo cello.[4] The significance of Wechselspeil I was perpetuated by Morthenson's status as a young member of Fylkingen, which he joined in the same year.[5] Following his time with Lindholm, Morthenson attended Uppsala University to study aesthetics[4] and furthered his study as a composer through private lessons with Gottfried Michael Köenig at the electronic music studio in Cologne.[6] He also studied with Heinz-Klaus Metzger, who would write a long preface to Morthenson's only book Non-figurative Musik in 1966.