on his European solo tours. Occasionally Landman performs together with Dutch sound artist Wessel Westerveld, who has built a collection of replicas of Luigi Russolos Intonarumori. Stichting De Stilte created a dance production with Landman playing live during the dance performances. Since 2015, he has built a series of kinetic objects made with motors and pendulums that together operate as a sound installation. He exhibits this project in addition to his on stage performances. 2016 Premier Guitar approached him for the second time for a guitar building request, which resulted in an experimental guitar built for Thurston Moore. Similar to the first project the building process was published as an article in Premier Guitar and he did a 20-minute YouTube interview with Thurston when he handed over the guitar. In the same year he developed a DIY daxophone workshop. In May/June 2017 he was artist-in-residence for one month at iii in The Hague where he developed the motorized sound installation Helicopters. For Lee Ranaldos Lost Ideas Festival in Menen, Belgium he developed a harmonic guitar based on a predecessor, invented by Branca in the early 80s, Ranaldo played in Glenn Brancas orchestra. At the invitation of Harman Kardon he built a 24 string drone sonometer for J.Views during a documentary shoot in the spring of 2018. In October 2018 he published an 8-page musicological essay in Soundest #1 in which he states that the configuration of the musical keyboard is mathematically based, rather than a cultural evolutionairy phenomenon. He shows the pattern in several non-Western scales such as the Indian 22 shruti system, the 19-tone scales on the Iranian tar and the Turkishsaz, an out-of-place Coptic artifact and his own tuning system applied on the Moodswinger. This explanation of the origin of the keyboard is in conflict with the Western consensus story that the pattern on the keyboard evolved culturally from originally seven white keys, adding one black key, followed by more into the twelve-tone Halberstadt Keyboard from 1361. In December that same year Musical Instrument Museum put on a large overview exhibition of his invented instruments. In 2019 he build a follow up series of rhythmic helicopters as a part of Nora Mulder's '7090 Abstraction Parc' that was exhibited at Gaudeamus Music Week, Open NDSM and several other Dutch festivals. During the Corona crisis his educational work and live performance stopped and he made a graphic novel after a