Jansen ran choral courses for secondary school students during the 1960s, and established the regional Choral Festival for Secondary Schools. In 1979, Jansen established the
New Zealand Youth Choir, serving as its musical director, and toured with the choir internationally in 1982. and he was the first person to arrange the New Zealand national anthem, "
God Defend New Zealand", with both English and
Māori lyrics, for the New Zealand Youth Choir's 1982 tour. Later that year, at the
2011 Rugby World Cup, Jansen was one of the conductors for choirs singing the national anthems before tournament matches. During 2012, Jansen spent six months in
Darwin as a choral consultant, which including teaching a conducting course at
Charles Darwin University, and working with indigenous children. ==Death==