A Dictionary of Music and Musicians/Bar
BAR. A vertical line drawn across the stave to divide a musical composition into portions of equal duration, and to indicate the periodical recurrence of the accent. The word bar is also commonly, though incorrectly, applied to the portion contained between any two such vertical lines, such portion being termed a 'measure.' In the accurately ancient 'measured music' (musica mensuralis—that is, music consisting of notes of various and determined length, and so called to distinguish it from the still older musica choralis or plana, in which all the notes were of the same length) there were no bars, the rhythm—which was always triple—being shown by the value of the notes. But as this value was not constant, being affected by the order in which the longer or shorter notes followed each other, doubtful cases occasionally arose, for the better understanding of which a sign called punctam divisionis was introduced, written . or ✔, which had the effect of separating the rhythmic periods without affecting the value of the notes, and thus corresponded precisely to the modern bar, of which it was the earliest precursor.
The employment of the bar dates from the beginning of the 16th century, and its object appears to have been in the first place to facilitate the reading of compositions written in score, by keeping the different parts properly under each other, rather than to mark the rhythmic divisions. One of the earliest instances of the use of the bar is found in Agricola's 'Musica Instrumentalis' (1529), in which the examples are written on a single stave of ten lines, the various parts being placed above each other on the same stave (the usual arrangement in the earliest scores), with bars drawn across the whole stave. Morley also in his 'Practical Musick' (1597) makes a similar use of bars in all examples which are given in score; but the introduction of the bar into the separate voice parts used for actual performance is of much later date. The works of Tallis (1575), Byrd (1610), and Gibbons (1612), were all published without bars, while in Ravenscroft's Psalter (1621) the end of each line of the verse is marked by a single bar. This single bar is termed by Butler ('Principles of Musick,' 1636) an imperfect close, which he says is introduced 'at the end of a strain, or any place in a song where all the parts meet and close before the end,' while the perfect close (the end of the whole composition) is to be marked with 'two bars athwart all the Rules.'
Henry Lawes appears to have been the first English musician who regularly employed bars in his compositions. His 'Ayres and Dialogues,' published in 1653, are barred throughout, though the 'Choice Psalmes put into Musick for Three Voices' by Henry and William Lawes, published only five years previously, is still without bars. The part-writing of the 'Choice Psalmes' is in many cases varied and even elaborate, and there must have been considerable difficulty in performing them, or indeed any of the compositions of that date, without the assistance of any signs of rhythmic division, especially as they were not printed in score, but only in separate parts. Their general character may be judged from the following example, which has been translated into modern notation and placed in score for greater convenience of reading. It may be observed that although without bars, the 'Choice Psalmes' are intended to be sung in common time, and that all have the sign at the commencement; some of the 'Ayres and Dialogues,' on the other hand, are in triple time, and are marked with the figure 3.
In modern music the use of bars is almost universal. Nevertheless there are some cases in which for a short time the designed irregularity of the rhythm requires that they should be dispensed with. An example of this is found in certain more or less extended passages termed cadences (not to be confounded with the harmonic cadence or close), which usually occur near the end of a composition, and serve the purpose of affording variety and displaying the powers of execution of the performer. (See the close of the Largo of Beethoven's Concerto in C minor, op. 37.) Also occasionally in passages in the style of fantasia, which are devoid of any definite rhythm, examples of which may be found in the Prelude of Handel's first Suite in A, in Emanuel Bach's Fantasia in C minor, at the beginning of the last movement of Beethoven's Sonata in B flat, op. 106, and in the third movement of Mendelssohn's Sonata, op. 6.
But even in this kind of unbarred music the relative value of the notes must be approximately if not absolutely preserved, and on this account it is often expedient during the study of such music to divide the passage into imaginary bars, not always necessarily of the same length, by the help of which its musical meaning becomes more readily intelligible. This has indeed been done by Von Bülow in regard to the passage in the Sonata above alluded to, and it is so published in the 'Instructive Edition of Beethoven's Works' (Stuttgart, Cotta, 1871), the result being a considerable gain in point of perspicuity. Similar instances will occur to every student of pianoforte music.A double bar, consisting of two parallel vertical lines, is always placed at the end of a composition, and sometimes at the close of a section or strain, especially if the strain has to be repeated, in which case the dots indicating repetition are placed on one or both sides of the double bar, according as they may be required. Unlike the single bar, the double bar does not indicate a rhythmic period, as it may occur in the middle or at any part of a measure, but merely signifies the rhetorical close of a portion of the composition complete in itself, or of the whole work.
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