Career
In 1885 he founded his company in Cologne-Mannsfeld. Organs by Seifert are found in the following churches:
1898 Saint Gereon"s Basilica, Cologne
1903 Christus-Church, Mönchengladbach,
1907 Kevelaer Basilica
1907 Quirinus Münster, Neuss
1909 Saint Peter"s Church, Kettwig
1912 Alternberg Cathedral, Altenberg
1912 Saint Matthias Church, Cologne-Bayenthal.