Sinds 2014 is Geert Jan actief als componist. Hij richt zich in de eerste plaats op muziek voor HaFaBra. Les krijgt hij van Wilbert Bulsink aan het ArtEZ conservatorium van Zwolle. Daarnaast volgde onder andere workshops bij Oliver Waespi, Philip Sparke en Edward Gregson. Geert Jan's muziek wordt uitgegeven bij Tower Editions.
“Each [work] is underpinned by a connection to original ideas and themes – ones that are not tossed away thoughtlessly as the works progress: The linear development of the music is bold and malleable, enabling the listener to understand the what, why and how he has developed the inspiration.”
“It’s the latest work from a musician who has carefully set out his compositional stall; one that retains a clearly defined thought process and structural identity through an engaging individuality of style. It’s music of intriguing clusters of harmony, texture and fluidity that draws the listener in through its layers of tonality.”
“At a time when emerging composers are finding it increasingly difficult to get their voices heard in the brass band world, it’s good to talk to a Dutchman who is determined to gain recognition by linking hard work to a desire not to lose his musical identity.”
“His thrilling and beautifull writing proved to be something of an audience favorite”