Danish cellist, conductor and composer, born 24 May 1896 in Nyborg, died 28 September 1975 at the Sankt Lukas Stiftelsen in Hellerup.

His father was a military musician and music director in Nyborg, so the young Johan was raised among musicians and then studied in the years 1913-1915 at the Music Conservatory with the cello as his main instrument. He then traveled to Paris (in the middle of World War I!) to further his education. There he came into contact with newer movements in French music. He also studied composition and composed a number of smaller works.

After returning home, he became the principal cellist in the Nordvästra Skånes Orkesterförening (Helsingborg Symphony Orchestra) and from 1919 bandmaster at Scala in Copenhagen. In that role he proved capable of conducting the theatre's large operetta performances and demonstrated his abilities as a theatre conductor to the best of his ability. However, he won a place as a cellist in the Royal Danish Orchestra in 1922, a position he held until he became conductor together with Georg Høeberg in 1925. After a short interruption, he resumed the position in 1932 and remained in it almost until his death in 1975, together with, among others, Egisto Tango and John Frandsen.

At the same time, he was the director of the Copenhagen Municipality's concerts in Fælledparken from 1934 to 1952 and from 1927 to 1946 conductor of the Student Choir.

His musical legacy consists of an opera, two ballets, some occasional cantatas, a few instrumental works, theatre music and a number of songs.

He was the brother of flautist Ernst Hye-Knudsen