Herman Gillis formed his first band (the Primitifs) when he was 18. He built a number of instruments for the band, including an air-scratcher, a drum machine (including self-made drum pads), a primitif computer system and a MIDI. When the Primitifs split up, the three remaining founders continued as The Passion of a Primitif and won second prise in Humo's Rock Rally in 1986. Their prize was to record an album produced by Jo Casters of Poésie Noire. Jo Casters asked Herman to join Poésie Noire as guitarist.

Around 1987, Herman began developing new ideas and programmed the first dance beats of several famous New Beat songs, such as Move Your Ass and Feel the Beat, Taste Of Sugar, etc. As Sherman, he became one of the most productive producers of the new beat era, working alongside Jo Casters (Morton) and Roland Beelen (Belluci) as Morton Sherman Bellucci (allegedly a parody of Stock, Aitken & Waterman). In 1988, reportedly after a journalist called Poésie Noire too “poppy”, he adopted the name Boris Mikulic and recorded as In Sotto Voce with Jo Casters (as Ilya Dimitrijevic), pretending to be a Yugoslavian band.

After the New Beat era, Herman went on to form and produced different dance acts, including MC Baker and Maree. Herman also played in the band Running Cow, later Volt, both featuring Daan. They were produced by Herman in cooperation with Wouter Van Belle. After Volt split up, Herman grew tired of the music industry and dedicated his time on the development of electronic gear. From 1993 to 1996, he spent his time entirely on making a new synthesizer and worked as a repair-man for artists and music stores. In 1996, the first prototypes of the Sherman Filterbank came out and became hugely successful. Herman has, in recent years, produced art and performances, including prototypes of an image synthesizer, in combination Sherman Filterbanks.

In 2010, he reunited with Jo Casters to record a new Poésie Noire record.