Born in Frankfurt am Main, Reulein studied Catholic church music at the
Hochschule für Musik und Darstellende Kunst Frankfurt am Main with
Wolfgang Schäfer and
Uwe Gronostay. After extended studies of organ improvisation with
Daniel Roth in Paris, he won several national and international competitions in this field, for example in 1993 the competition of Belgian radio and the second prize and the public's prize at the
Festival Europäische Kirchenmusik in
Schwäbisch Gmünd. He continued his studies of interpretations with
Ludger Lohmann,
Ewald Kooiman and
Wolfgang Rübsam. He took master classes with choral conductors such as
Eric Ericson and
Helmuth Rilling. From 1991, Reulein was the church musician at the
Heilig Geist in Frankfurt-Riederwald, from 2000 he has held the position at
Liebfrauen in the centre of Frankfurt. There he directs a vocal ensemble, the choir Collegium Vocale, the orchestra Collegium Musicum and the youth choir Capuccinis. He was instrumental in having a new organ built which completed in 2008. Reulein inaugurated it in a concert on 9 August, playing works by Bach,
César Franck and improvisation. Reulein is known for composing new songs for church services (), many of them on texts by
Eugen Eckert. Reulein was from 2000 until 2005 the head of the
Arbeitskreis Kirchenmusik und Jugendseelsorge im Bistum Limburg, caring about more appropriate church music for young people. Reulein has been an instructor of liturgical organ playing and improvisation at the Frankfurt Hochschule für Musik und Darstellende Kunst from 2002. He was appointed (regional cantor) for Frankfurt in 2008. In 2014, Reulein recorded at Liebfrauen a CD of
Französische Orgelsymphonik (French symphonic organ music) with works by
Léon Boëllmann,
Camille Saint-Saëns,
Alexandre Guilmant and
Charles-Marie Widor. '' on 6 November 2016 at the Limburg Cathedral, conducted by the composer at
St. Martin, Idstein, to Franz Fink (left) who conducted and
Roman Twardy on 7 May 2023 He was commissioned to compose an
oratorio to celebrate in 2016 the 50th anniversary of church music in the
Catholic Diocese of Limburg, presenting different styles of church music. The text by
Helmut Schlegel, titled ''
Laudato si' – Ein franziskanisches Magnificat (A Franciscan Magnificat) includes the Latin Magnificat, writings by Francis of Assisi and Clare of Assisi, writings by Pope Francis from the German version of Laudato si''' to German, and other sacred texts. Reulein scored the work for five soloists, children's choir,
Choralschola, mixed choir, organ and orchestra. It was published by the
Dehm-Verlag in Limburg in 2016 and first performed in the
Limburg Cathedral on 6 November 2016, conducted by the composer. == Works ==