Born in 1929 in Meppen an der Ems. Began studying musics at the Detmold Nordwestdeutsche Musikakademie in 1948, composition with Günter Bialas, conducting with Kurt Thomas, organ with Hans
Heintze and Michael Schneider, piano and theory with Theodor Kaufmann. Zacher later visited courses with Olivier Messiaen, Stefan Wolpe, Pierre Boulez, Karlheinz Stockhausen.
In 1957, Zacher became organist at the Deutsche Evangelische Kirche in Santiago de Chile, in 1960 at the Lutherkirche in Hamburg Wellingsbüttel, where he staid for twelve years. He initiated the construction of a new organ by Karl Schuke. Zacher performed première performances by Kagel, Ligeti, Otte, Englert, Schnebel, Allende-Blin und Isang Yun, all of which dedicated these organ works to the said performer. Since 1970, Zacher led the department of Evangelische Kirchenmusik at the Folkwang Music University in Essen.
Zacher died in Essen June 6, 2014.