( The later pope St. Gregory I the Great is not known to have composed any Gregorian chant, the plainsong or " Romish chant ".

* Communion ( chant ), the Gregorian chant that accompanies this rite

Western musical notation was originally created to preserve the lines of Gregorian chant, which before its invention was taught as an oral tradition in monastic communities.

During the Middle Ages a rich hymnody developed in the form of Gregorian chant or plainsong.

Beneventan chant is largely defined by its role in the liturgy of the Beneventan rite ; many Beneventan chants were assigned multiple roles when inserted into Gregorian chantbooks, appearing variously as antiphons, offertories, and communions, for example.

It was eventually supplanted by the Gregorian chant in the 11th century.

* Gregorian mode, a pitch organization of Gregorian chant

During the earlier mediaeval period, the liturgical genre, predominantly Gregorian chant, was monophonic.

" By the middle of the 9th century, however, a form of neumatic notation began to develop in monasteries in Europe as a mnemonic device for Gregorian chant, using symbols known as neumes ; the earliest surviving musical notation of this type is in the Musica disciplina of Aurelian of Réôme, from about 850.

These were two or three part compositions in which several different texts, sometimes in different vernacular languages, were sung simultaneously over a Latin cantus firmus that once again was usually adapted from a passage of Gregorian chant.

The earliest designs of keyboards were based heavily on the notes used in Gregorian chant ( the seven diatonic notes plus B-flat ) and as such would often include B and B both as diatonic " white notes ," with the B at the leftmost side of the keyboard and the B at the rightmost.

In Britain, the Yardbirds, with Jeff Beck as their guitarist, increasingly moved into psychedelic territory, adding up-tempo improvised " rave ups ", Gregorian chant and world music ( in particular Indian ) influences to their songs, including " Still I'm Sad " ( 1965 ) and " Over Under Sideways Down " ( 1966 ), and singles such as " Heart Full of Soul " ( 1965 ), " Shapes of Things " ( 1966 ) and " Happenings Ten Years Time Ago " ( 1966 ).

* Gregorian chant semiology is a current avenue of palaeographical research in Gregorian chant which is revising the Solesmes school of interpretation.

At Charlemagne's request Pope Adrian I sent distinguished chanters from Rome, who propagated the use of the Gregorian chant.

Yoko Kanno and Hajime Mizoguchi composed and produced the series ' musical themes and background, incorporating a variety of styles including contemporary, classical, and Gregorian chant.

* Pope Gregory I codifies what comes to be known as Gregorian chant.

Most musicians during this time period catered to the influences of the Roman Catholic Church, providing arrangements structured around Gregorian chant structure and Masses from church texts.

The modern accidental signs derive from the round and square small letter b used in Gregorian chant manuscripts to signify the two pitches of B, the only note that could be altered.

April is the fourth month of the year in the Julian and Gregorian calendars, and one of four months with a length of 30 days.

August ( ) is the eighth month of the year in the Julian and Gregorian Calendars and one of seven months with a length of 31 days.

AD ( Anno Domini ) is a designation used to label years following 1 BC in the Julian and Gregorian calendars.

The early Roman calendar, which had no way of designating the days of the winter months other than to lump them together as " winter ", is an example of an incomplete calendar, while the Gregorian calendar is an example of a complete calendar.

Calendars in widespread use today include the Gregorian calendar, which is the de facto international standard, and is used almost everywhere in the world for civil purposes, including in the People's Republic of China and India ( along with the Indian national calendar ).

It is used to date events in most of the Muslim countries ( concurrently with the Gregorian calendar ), and used by Muslims everywhere to determine the proper day on which to celebrate Islamic holy days and festivals.

While the Gregorian calendar is widely used in Israel's business and day-to-day affairs, the Hebrew calendar, used by Jews worldwide for religious and cultural affairs, also influences civil matters in Israel ( such as national holidays ) and can be used there for business dealings ( such as for the dating of checks ).

Even where there is a commonly used calendar such as the Gregorian calendar, alternate calendars may also be used, such as a fiscal calendar or the astronomical year numbering system.

Week 1 is always the week that contains 4 January in the Gregorian calendar.

Calculating the calendar of a previous year ( for the Gregorian calendar taking account of the week ) is a relatively easy matter when Easter Sunday is not included on the calendar.

It is common to display the Gregorian calendar in separate monthly grids of seven columns ( from Monday to Sunday, or Sunday to Saturday depending on which day is considered to start the week-this varies according to country ) and five to six rows ( or rarely, four rows when the month of February contains 28 days beginning on the first day of the week ), with the day of the month numbered in each cell, beginning with 1.

The astronomer's mean tropical year which is averaged over equinoxes and solstices is currently 365. 24219 days, slightly shorter than the average length of the year in most calendars, but the astronomer's value changes over time, so William Herschel's suggested correction to the Gregorian calendar may become unnecessary by the year 4000.

The Gregorian calendar, and the year-numbering system associated with it, is the calendar system with most widespread use in the world today.

In most of East Asia today, the Gregorian calendar is used for day-to-day activities, but the Chinese calendar is still used for marking traditional East Asian holidays such as the Chinese New Year, the Duan Wu festival, and the Mid-Autumn Festival, and in astrology, such as choosing the most auspicious date for a wedding or the opening of a building.

In China, the traditional calendar is known as the " agricultural calendar " ( 農曆 / 农历 ) while the Gregorian calendar is known as the " common calendar " ( 公曆 / 公历 ).

For example, the Gregorian calendar has no inherent dependence on the seven-day week, but in Western society the two are used together, and calendar tools indicate both the Gregorian date and the day of week.

For example, " 24 " is ten days after " 14 " in the Gregorian calendar.

In years 2200 – 2299, for example, the start of Passover will be about a month later than Gregorian Easter in four years out of nineteen.

For example, in the Gregorian calendar ( a common solar calendar ), February in a leap year has 29 days instead of the usual 28, so the year lasts 366 days instead of the usual 365.

For example during eight centuries the calendar belonging to the Christian era, which era was taken in use in the 8th century by Bede, was the Julian calendar, but after the year 1582 it was the Gregorian calendar.

The 1931 pocket calendar displayed here is a rare example that excluded the five national holidays, enabling the remaining 360 days of the Gregorian year to be displayed as a grid with five rows labeled for each day of the five-day week.

For example, in Sumer, the birthplace of the modern sexagesimal system, there were 12 months of 29 or 30 days apiece, much like the modern Gregorian calendar.

This book deals with correct performance conventions and procedures relevant to different periods and styles ( for example Gregorian intonation, divisions upon parts, French baroque over-dotting, etc .).

For example, if the complaint alleges that an event occurred on a specified date and that date establishes on the face of the complaint that the party's filing was too late ( beyond the applicable statute of limitations ), a judge can take judicial notice of a standard Gregorian calendar, calculate the difference between the present date and the date the complaint alleges a wrongful act occurred, and determine if the complaint was timely filed.

For example, the Gregorian calendar numbers its years in the Western Christian era ( the Coptic and Ethiopic churches have their own Christian eras, see below ).

On many releases, the jazz and classical sides of ECM are combined: For example, Garbarek's Officium ( 1994 ) features him playing saxophone solos over the Hilliard Ensemble singing Gregorian chant, early polyphony and Renaissance works.

For example, St. Nicholas date is December 6, but by Julian calendar this date is 13 days later, when by Gregorian calendar is December 19.

However, because not all months have the same number of days, this doesn't always work – for example, six months after an August 30 birthday would be February 30, which doesn't exist in the Gregorian calendar.

For example, the future epoch J2100. 0 will be exactly 36, 525 days ( one Julian century ) from J2000. 0 on ( the dates will still agree because the Gregorian century 2000 – 2100 will have the same number of days as a Julian century ).

For example, in the next 1000 years, seven days will be dropped from the Gregorian calendar but not from 1000 Julian years, so J3000 will be.

Graduals are among the most florid and melismatic of all Gregorian chants ; Clamaverunt iusti, for example, has melismas with up to 66 notes.

The court decided that the Calendar year referred to was the 365 day Gregorian year ( and not for example the 360 day Hijri year ).

For example, Christmas Day ( December 25 ) on the Julian Calendar falls on January 7 of the modern Gregorian Calendar.

The names of the months are the same as the Gregorian calendar, except for a " 1 " or " 2 " in front to indicate the first or second occurrence of that month ( for example, 1 January, 2 January, 1 February, 2 February ).

The League also turned its attention to the question of Bahá ' í terminology in Esperanto, for example the names of the 19 months of the Bahá ' í Calendar ( with issue No. 15 of the " Komuna Bahaa Letero ", May 1975, a calendar was enclosed, in which the Bahá ' í and Gregorian calendars were placed side by side ).