The word Sequens (sequence) has a double meaning.

The first one, musically speaking, is the repetition of a motif or harmony at a different pitch. In this piece opening chords are slowly melting down and by the end of the section find themselves unchanged an octave lower.
The second one is liturgical and means medieval singing, shown in the pedal solo at the beginning. In this way, Jan Welmers combines these two meanings and develops this idea with pleasure for almost 25 minutes, putting us in a trance and letting us forget about the concept of time.

The whole piece consists of four parts (ABCD).
A - a combination of two meanings of the word sequence. Gregorian chant sounds in the pedal, meanwhile the hands are playing a chain of descending chords.
B 4:11 - lower layer, in the left hand - sequence (singing) in a faster way. At the top - short motives.
C 7:06 - the structure is comparable to part A, with the difference that the harmonies are written in a minimal (repetitive) style.
D 14:27 - the heart of the entire composition, which combines all structural elements.

Disposition of the great Seifert organ in St. Matthias, Berlin
Jan WELMERS: Sequens (minimal music, 1979)
Vladimir Magalashvili plays Sequens (1979) by Dutch composer Jan Welmers on the Great Seifert organ (IV/77/P), 1958/1974 in St. Matthias, Berlin-Schöneberg.
Recorded on the Steinmeyer-Orgel (III/71/P), Opus 1400, 1925 in Kirche Ss. Corpus Christi, Berlin.

Registration:
Intro: L.h. (II man) Unda maris 8' + Wienerflöte 8' ; R.h./Solo (I man) Doppelflöte 8' (+Glocken)
Choral: (III man) Lieblichgedeckt 8' + Fernflöte 4' + Vox Humana 8' + Tremulo

Disposition of the Steinmeyer-Orgel in Ss. Corpus Christi, Berlin

Franz Xaver Gruber (1787 - 1863) - Stille Nacht, heilige Nacht
Played and arranged by Vladimir Magalashvil
Made on
Tilda