# Bar

noun: something that prevents another thing from happening
noun: an order stating that something is not allowed
MUSIC: In musical notation, a bar (or measure) is a segment of time corresponding to a specific number of beats in which each beat is represented by a particular note value and the boundaries of the bar are indicated by vertical bar lines. Dividing music into bars provides regular reference points to pinpoint locations within a musical composition. It also makes written music easier to follow, since each bar of staff symbols can be read and played as a batch.

The bar is a unit of pressure equal to 100 kilopascals, and roughly equal to the atmospheric pressure on Earth at sea level. Other units derived from the bar are the megabar (symbol: Mbar), kilobar (symbol: kbar), decibar (symbol: dbar), centibar (symbol: cbar), and millibar (symbol: mbar or mb). They are not SI units, nor are they cgs units, but they are accepted for use with the SI. The bar is widely used in descriptions of pressure because it is only about 1% smaller than the atmosphere, and is legally recognized in countries of the European Union.

Except for the power of ten, the definition of bar fits in the sequence of SI pressure units (Pa, kPa, MPa), namely, 1 bar â‰¡ 100,000 Pa = 100 kPa = 0.1 MPa. This is in contrast to the well-known unit of pressure, atmosphere, which now is defined to be 1.01325 bar exactly.

The bar and the millibar were introduced by the British meteorologist William Napier Shaw in 1909. William Napier Shaw was the director of the Meteorological Office in London from 1907 to 1920.

Barg is a unit of gauge pressure, i.e. pressure in bars above ambient or atmospheric pressure; see Absolute pressure and gauge pressure below. (wikipedia)

Hughes
"Harmony must be looked at in two ways at least: first, up the score from bottom to top—the perpendicular view; second, along the score from side to side—the horizontal view. Then as to its periods or pulsations—its to and fro, its flow and ebb. This brings us to rhythm and measure. At the bottom of these lie what is called stress or accentemission and remission—strong and weak: of these the bar in modern music is an outward and visible sign of certain facts which ought to be in the music, but which, if not in the music, the presence of the bar is of no avail. The bar cannot give stress or accent. 'Wherever there is time, there must be accent;'* but the tick of a clock has no accent. Hullah (or Chorley) should have said life." "The semitone makes music. What operation has it upon the accent or to and fro? It creates the call, it supplies the answer." [This point, I believe, Dr. Gauntlett never alluded to with me, and I have feared that making no difference between tones and semitones might be considered a difficulty with regard to the scheme. In the working of the natural laws of harmony, they must all equally be employed.—F. J. H.] "Art (grand and true) does not depend upon the teaching of facts. The head is of less importance than the heart. Unless the tone of feeling, the habit and disposition, be well fixed, nothing enduring can come out of the misdirected artist." [Harmonies of Tones and Colours, Fragments from the Last Note-book, page 50]