Jan Stoeckart (November 1927 – January 2017) was a Dutch composer, conductor and radio producer, who often worked under various pseudonyms, including Willy Faust, Peter Milray, Julius Steffaro and Jack Trombey. Graduating from the Amsterdam Conservatory in 1950, he began his career as a trombone and double bass player, and as a music producer for various radio shows. He composed and arranged for Dutch films and brass bands, and worked with the Metropole Orchestra and the Dutch Promenade Orchestra.

In the early 1960s, the conductor Hugo de Groot introduced Stoeckart to the de Wolfe music publishing house in London, and he obtained a contract to compose library music for that company. He wrote in excess of 1200 works; his biggest success was with Eye Level, the theme tune to the British TV series Van der Valk in the early 1970s, penned under the name of Jack Trombey.

The piece became a big hit with viewers and record buyers, and the recording – made by the Simon Park Orchestra – reached no. 1 in the UK singles charts in 1973.

As Julius Steffaro, Stoeckart composed theme and music for the famous Dutch TV series "Floris", 1969, starring Rutger Hauer and directed by Paul Verhoeven.