[4][5] Wintergatan is made up of four musicians, Martin Molin, Evelina Hägglund, David Zandén and Marcus Sjöberg.

[6] The band uses a variety of unconventional instruments including the Modulin, a ribbon controlled synthesizer built from Doepfer eurorack modules in the likeness of a violin,[7] the Moog Theremini digital theremin, an electric autoharp, a hammered dulcimer, a self-built punch-card music box, a slide projector, a musical saw, and a typewriter for use as percussion.

Between December 2014 and March 2016, the band uploaded several YouTube videos featuring Martin Molin documenting the construction of a music box that uses marbles to play instruments.

The music score is stored on two programmable wheels that utilize Lego Technic beams and stud connectors to trigger armatures to release the marbles.

[12][13][14][15][16] Martin Molin stopped building the MMX at the end of 2021 after realizing the design would not be robust or reliable enough to go on tour with.