Doppelstrich

From O Lux beata Trinitas by Johann Bahr, in the Visby Tablature

The double bar or double line (de "Doppelstrich" or "Doppelsenkrechte") is an ornament that appeared primarily in Baroque music in northern Germany.

Appearence

The opening notes from Fantasia a 6 from D-B Mus. Ms. Lynar b 3

Like all ornaments in New German Tablature, the Doppelstrich appears below the note which it applies to. It appears as two parallel lines either vertical or rotated slightly clock-wise.

From Peter Heydorn, Fuga in g, in Lowell Mason Codex

The Doppelstrich occasionally appears in German manuscripts in stave notation. Here it usually appears above or below the note, and not intersecting the stem of the note as in English virginal music^{[Citation needed]}.

From Vater Unser im Himmelreich by Dietrich Buxtehude from D-B Mus.ms. 30280

Additionally, an interesting ornament appears in D-B Mus.ms. 30280 which appears to be a notehead with a Doppelstrich intersecting the stem.

Execution

There is some evidence from the area of the North German organ school that allows an approximation of the customs of the time for the execution of ornaments. One of the most important findings is a possible adaptation of the length of an ornament to the length of the underlying note. Michael Praetorius‘ (1571-1621) Syntagma musicum (1619), Johann Adam Reincken‘s (1623/43-1722) Hortvs Musicvs (1687) and explanations by Martin Heinrich Fuhrmann (1669-1745) show that trills - or “trillo” or “tremuli” - begin with the main note. A correspondence between the symbol || and Sweelinck‘s // is obvious and requires a situation-dependent execution based on the flow direction of the music.

Several categories of ornaments can be found from the late 16th to the 17th century:

1. Mordent (short) and Tremulus descendens (long) with a lower secondary note and beginning on the main note.
2. Tremoletti (short) and Tremulus ascendens (long) analogously with an upper secondary note.
3. Groppi (long) with the upper secondary note as a written-out final clause for cadences.

While groppi were always written out, the first two types can be produced with a Doppelstrich. This can be seen from the fingering markings in the Helmstadt tablature, D-W Cod. Guelf. 1055 Helmst. It is important to note that the third finger is always the main finger in the execution of ornaments, as can be seen from the tablature booklet of Loysae Charlotten, “Marggrävin und Churfl. Frewlein zu Brandenburg” from 1632 (St. Petersburg, Biblioteka Akademii Nauk, Ms, XXL.L.5) - as well as a fourth type of ornament:

4. ornaments beginning with the upper secondary note.

As Harald Vogel has pointed out, the type of ornament can be identified from the fingerings in this tablature. In general, however, ornaments beginning with a main note are much more common. The Hamburg manuscript D-ND S.M.G. 1691 also only achieves the beginning of trills with the secondary note around 1710 by means of grace notes.

In connection with the transmission of Buxtehude's suites and variations, it can be proven that around 1700 the tablature symbols double vertical line, double cross and wavy line were identified as the "agréments" cadence or tremblement, pincement or coulé. With all due caution, one can infer that the symbol of the double vertical line often found in the tablatures signifies an ornament which uses the upper auxiliary note, ... .