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HEATING A BUILDING

2.1 Naada, shruti, swara [Musical sound or tone, microtone, note]

Naada is a musical sound. It is a series of regular vibrations in a medium like air (as opposed to irregular vibrations, which would be heard as noise). The frequency of a vibration decides the pitch of the sound it represents (how high or low the sound feels to the ear). The frequency is reported in a unit called Hertz (Hz). The frequency range of a sound the human ear can hear is 20 Hz to 20,000 Hz.

Now, as an example, take a sound (or tone) having a frequency of 100 Hz. Another sound, having twice the frequency, that is, 200 Hz, will sound the same. But it will sound 'higher'. The frequency ratio 200:100, which is 2:1, represents what is called an octave. The number of sounds that the human ear can hear, in an octave, is infinite. But the number of sounds that it can discern, differentiate, or grasp, is 22. They are called shruti-s (microtones). Shruti has been variously translated as: microtone, microtonic interval, interval, step etc. It is mainly determined through fine auditory perception

So, to continue with our example, there exist 22 shruti-s, starting with the first shruti on the starting point of 100 Hertz. Taking the sound represented by 100 Hz as the point of reference, we get 22 ratios. The 23rd ratio takes us to the sound represented by 200 Hz. These ratios are called intervals. The intervals are measured in relation to the reference sound (100 Hz in our example). The octave is represented by the ratio 200:100, or the interval 2:1. This sound of reference is called tonic, key, or "Sa", etc. In Indian musical terminology, it is known as shadja, "Sa" for short. It is represented by the symbol S. Out of the 22 shruti-s, 7 are selected to form a musical scale. The tonic is fixed first, followed by 6 more shruti-s to form a 7-ladder scale. These 7 sounds, or tones, are called swara-s (or notes). The tonic, in our example, would fall on the sound represented by 100 Hz. This would be our "Sa (S)". The Sa would be followed by 6 more notes, 7 in all. The 8th note, the sound represented by 200 Hz, would sound like the tonic, but it would sound "higher". The 7 notes form the "saptaka" of Indian music; the 8 notes-- the eighth note being the "higher" Sa -- form the "octave" of the Western music. The seven notes are named as follows:

 

shadja, "Sa" for short, symbol S; rishabha, "Re", R; gandhara, "Ga", G; madhyama, "Ma", m; panchama, "Pa", P; dhaivata, "Dha", D; and the 7th, nishada, "Ni", N.

For convenience, let us call the Western musical note, C, as our tonic, the "Sa". Then the seven notes would be: C, the "Sa"; D, "Re"; E, "Ga"; F, "Ma"; G, "Pa"; A, "Dha"; and the 7th, B, "Ni".The first and the fifth notes, namely C (Sa) and G (Pa), are regarded immutable ("achala"). The remaining 5 notes have two states each. Thus we have 12 notes in an octave. The 12 notes are designated short names and symbols as under:



# Name Symbol Indian Symbol Western
Sa shuddha (natural) S C
Re komala (flat) r D flat
Re shuddha (natural) R D
Ga komala (flat) g E flat
Ga shuddha (natural) G E
Ma shuddha (natural) m F
Ma teevra (sharp) M F sharp
Pa shuddha (natural) P G
Dha komala (flat) d A flat
Dha shuddha (natural) D A
Ni komala (flat) n B flat
Ni shuddha (natural) N B

 

The octave can be divided into two equal parts: the lower tetrachord, consisting of C-D-E-F, and the upper tetrachord, made up of G-A-B-C. This last-mentioned C has the interval 2:1 with the first C in the lower tetrachord. The lower tetrachord is called "poorvaanga" (poorva + anga), the upper tetrachord, "uttaraanga" (uttara + anga) in Indian musicology. Further, Full expression of Indian music requires up to 3 octaves. They are: the "mandra saptaka" (lower octave), the "madhya saptaka" (middle octave), and the "taara saptaka" (higher octave). Note: The notes in Western music use the tempered scale, while in Indian music the notes use the natural harmonic scale.

2.2 Thaat [Scale]

A thaat (scale) is a 7-ladder scale, made up of 7 primary notes. A thaat must contain all 7 notes, each in any one of the "shuddha", "komala", or "teevra" state. The word thaat is synonymous with "mela". We have the following 10 thaat-s, with their names and the included 7 notes in each:

Thaat Notes

1 Bilawal S-R-G-m-P-D-N

2 Khamaj S-R-G-m-P-D-n

3 Bhairav S-r-G-m-P-d-N

4 Kafi S-R-g-m-P-D-n

5 Asavari S-R-g-m-P-d-n

6 bhairavi S-r-g-m-P-d-n

7 Kalyan S-R-G-M-P-D-N

8 Marva S-r-G-M-P-D-N

9 Poorvi S-r-G-M-P-d-N

10 Todi S-r-g-M-P-d-N

11 *Kirvani S-R-g-m-P-d-N

* Added, being important as the harmonic minor scale.

 

Each Thaat is a group of seven notes from which raga-s have been formed (or can be formed). The musicians perform raga-s, never thaat-s. Note: The notes in Western music use the tempered scale, while in Indian music the notes use the natural harmonic scale.

The names of these thaat-s happen to be the very names of raga-s, too. But a thaat does not have any aesthetic value. So it is never performed. On the other hand, a raga has aesthetic appeal, and is performed by musicians.

2.3 Raga [Sometimes translated as "Mode", though imperfectly]

The concept associated with the term" raga" is highly developed and complex. It defies any definition or description. We can, at best, enumerate some of the characteristics of the raga. Even then its concept eludes us. The only way to grasp the concept of the raga is to listen to its development over prolonged periods of time and repeatedly. It is like learning a new language: However enjoyable, it requires consistent and continuous effort. Let us take up some of the characteristics of the raga:

1. The raga must be aesthetically pleasing. It must delight the heart of the listener. It must be capable of existing in its own right, as an individual entity, with unique aesthetical value.

2. The development of a raga is. in principle, constant attainment of aesthetic tensions, followed by resolutions, through various degrees of sonance (consonance and dissonance). This is achieved by the use of the permissible notes, singly or in combination, through the movements in three octaves. There are regulations that govern these movements.

3. Basically, a raga is capable of being developed into an infinite number of melodic patterns, following certain guidelines.

4. A raga should be capable of being classified into one of the thaat-s.

5. A raga cannot be formed out of less than 5 notes. "Sa" has to be present as the reference note. Both "Ma" (the fourth) and "Pa" (the fifth) cannot be simultaneously omitted from the raga. So, it must have the following notes: SA; one of the Re or Ga; Ma or Pa; one of the Dha or Ni, Further, if only one of the Ma/Pa is present, the raga must include either both Re and Ga, or both Dha and Ni, so as to achieve a total of 5 notes.

5. It cannot include two states (out of the three possible states: shuddha, komala, and teevra) of same note consecutively.

6. The raga must follow the time theory. This means that a raga can be performed only at its stipulated time of the day (or night, or a season of the year).

2.4 Classification of Raga-s

There are several ways in which a raga can be classified. The clasification may be based on

(A) The number of notes which comprise the raga. We have three types: (i) "audava", with 5 notes; (ii) "shadava", with 6 notes; (iii) "sampoorna", with 7 notes.

(B) Tempo of movement. (i) "alapa-pradhana", if slow movement brings out the characteristics of a raga better; (ii) "taana-pradhana", if the raga sounds better in fast movement.

(C) The importance of the tetrachord in the development of the raga. (i) "poorvanga-pradhana", if the development of the raga is more prominent in the lower tetrachord; (ii) "uttaranga-pradhana", if the development of the raga is more prominent in the upper tetrachord.

(D) Grammar and Syntax of the raga. (i) "shuddha" (uncontaminated); (ii) "chhaya-laga", if it reminds the listener of another raga; (iii) "samkeerna", if it is a mixture of many raga-s.

(E) Nature of its movements. (i) "satala", if its developmental movements are straightforward and plain; (ii) if the movements are complex and zigzag.

2.5 The Defining Elements in the Raga

The following elements define the grammar, syntax and aesthetics of a raga:

(1) Graha. It used to be the starting note of a raga. It has lost its significance in today's improvised style of singing.

(2) Amsha. It is the most frequently used note in a raga. This term is not in use in today's music.

(3) Nyasa. It is the ending note in the performance of a raga. Again, this term is not used much these days.

(4) to (8). Taara, mandra, apanyasa, sanyasa, vinyasa. These terms are not in use any more.

(9) Alpatva. It indicates very little use of a note (or notes) in a raga.

(10) Bahutva. It indicates very frequent use of a note (or notes) in a raga. It is effected by either repeated use of a note, or by emphasing and prolonging a note.

(11) Tirobhava. It means hiding the prominent features of a raga when perfoming it.

(12) Avirbhava. It means highlighting the prominent features of a raga when perfoming it. It is used to indiate showing the prominent features of a raga again, after hiding it (in tirobhava).

(13) to (16). Vadi, samvadi, anuvadi, and vivadi. These are treated separately in 2.6 below.

2.6 Vadi, Samvadi, Anuvadi, Vivadi [ Sonant, Consonant, Assonant, Dissonant]

Vadi. It has been described as the King of the notes occuring in a raga. It dominates the development of the raga, it is accentuated, it is emphasised. The melodic patterns are woven around the vadi. If it is located in "poorvanga"(the lower tetrachord), the raga is developed with greater emphasis in the lower tetrachord, Similarly for "uttaranga" (the upper tetrachord). See 2.4(C). Also, if the vadi of a raga is located in the "poorvanga', that raga is performed at any time except the morning. If the vadi of a raga is located in the "uttaranga', that raga is performed in the morning.

 

Samvadi. It has been given importance next only to the King (vadi). Samvadi also enjoys great importance in the development of a raga. If the vadi of a raga is located in "poorvanga"(the lower tetrachord), its samvadi will be located in the "uttaranga" (the upper tetrachord). And vice versa.

The samvadi is always a fifth or a fourth in relation to the vadi. The relationship of the fifth is called "shadja-panchama bhava". The relationship of the fourth is called "shadja-madhyama bhava". Vadi-samvadi relationships exemplify perfect consonance.

 

Anuvadi. The notes occuring in a raga, apart from the vadi and the samvadi, are called anuvadi notes. They bring the number of notes in the raga to atleast five. They help in creating aesthetic tension, to be followed by resolution. (See 2.3, 2). Sometimes. an anuvadi can have great importance, the same as, or next only to samvadi. Such an anuvadi can be called "pranuvadi". Very often, an anuvadi acts as the leading note, creating aesthetic tension, till it leads to "Sa" (especially in higher octave), resolving the tension.

 

Vivadi. They are the notes which do not occur in a raga. However, quite often, a vivadi is included, in a specific way, in the develpoment of a raga. This is because a vivadi can embellish a raga by making it sound exceptionally charming.

2.7 Aroha, avaroha [Ascending, Descending]

Aroha is the successively ascending notes of a raga, starting on the tonic ("Sa"), and ending in the "Sa" in the higher octave.

Avaroha is the successively descending notes of a raga, starting on the "Sa" in the higher octave.and ending on the tonic ("Sa"), it is the opposite of aroha.

Aroha-avaroha indicate the notes comprising a raga. They are useful in a very general way: they do not specify characteristics of a raga. In fact, it is possible for two raga-s to have the same aroha-avaroha, though the ragas may be totally different aesthetically.

2.8 Jaati-s of a raga [Classification of a raga]

As shown in 2.4 (A), a raga may be classified, based on the number of notes it contains. Thus, we have three types: (i) "audava", with 5 notes; (ii) "shadava", with 6 notes; (iii) "sampoorna", with 7 notes. Depending on the number of notes in the aroha, and in the avaroha, we derive the following nine theoretical classes:

(i) audava-audava: 5 notes in aroha, 5 in avaroha.

(ii) audava-shadava: 5 notes in aroha, 6 in avaroha.

(iii) audava-sampoorna: 5 notes in aroha, 7 in avaroha.

(iv) shadava-audava: 6 notes in aroha, 5 in avaroha.

(v) shadava-shadava: 6 notes in aroha, 6 in avaroha.

(vi) shadava-sampoorna: 6 notes in aroha, 7 in avaroha.

(vii) sampoorna-sampoorna: 7 notes in aroha, 7 in avaroha.

(viii) sampoorna-shadava: 7 notes in aroha, 6 in avaroha.

(ix) sampoorna-audava: 7 notes in aroha, 5 in avaroha.

2.9 Time Theory of Raga-s [Time of Performance]

According to the time theory, a raga can be performed only at a particular time assigned to it, out of 24 hours of the day, or, in some cases, a particular season of the year is assigned. It is not clear why this is so; but the theory is strictly followed even today. See 2.4 (C). "poorvanga-pradhana" raga-s are sung during the time period 12 noon to 12 midnight. "uttaranga-pradhana" raga-s are sung during the time period 12 midnight to 12 noon. In addition, each raga has been assigned a particular "prahara" only in which it can be performed. A "prahara" is 90 minutes.

 

Timewise, the raga-s are divided into the morning raga-s, the midday/midnight raga-s, the twilight raga-s, and the night raga-s. In this context, the following generalizations have been observed

(i) Raga-s with shuddha Re (D), Ga (E), Dha (A) and Ni (B) are performed in the first quarter of morning or night.

(ii) Raga-s with komala Ga (E flat) and Ni (B flat) are performed in the middle of the day or night.

(iii) Raga-s with Sa (C), Ma (F), and Pa (G) as prominent notes, are performed in the last quarter of day or night.

(iv) Raga-s performed from afternoon till midnight, contian teevra Ma (F sharp).

(v) The raga-s with komala Re (D flat) and Dha (A flat), are performed at the twilight (morning as well as evening). Such raga-s are called "sandhi-prakasha" raga-s. Also, they often use both shuddha Ma (F) and teevra Ma (F sharp).

Note: There are two exceptions : On being ordered by a King, and when learning from your Guru, you can perform any raga at any time.

2.10 Taal, Laya [Rhythm, Tempo]

Various terms associated with the rhythmic concept in Hindustani music are: taal (rhythm), matra (beat), sama, khali, taali, khanda (division), avartana (cycle), laya (tempo), Tempo types : vilambita (slow), madhya (moderate), and druta (fast), bol (mnemonic sounds), and theka (basic cycle of bol-s).

 

Taala is a rhythmic cycle (avartana). It consists of a certain, fixed number of beats (matra). A beat is the duration of silence between the first and the next count. The count can be done by clapping, or counting numbers, or saying the sounds of the bol. The number of beats varies from one taal to another. Each taal has a name. For example, the taal called Teental, is a cycle of 16 beats. On completion of 16 beats, the counting starts again from 1 through 16. And so on. Counting is done at a uniform, steady pace. If counting is slow, the resulting tempo will be slow (vilambita laya). If counting takes place at a moderate speed, the tempo will be moderate (madhya laya). Fast counting will result in fast tempo (druta laya). The first beat of the rhythmic cycle is the most important one. it is called the sama (pronounced like the word "sum"). A little beyond half way, another important beat occurs. It is called khali. It means "empty". it is so called because it is assigned negative weight (taking something out). Taali means clapping. It occurs at different place(s), depending upon the taal. The cycle of a taal is divided into parts, each part is called a khand. The bol-s of a taal are a set on mnemonic sounds. Some examples of bol-s are: taa, naa, dhin, tin, dhaa, dhin,etc. They are the alphabets -- about 15 in number -- of the language of taal. taal-s are played on percussion instruments like the tabla and pakhavaj, Tabla is the most popular percussion instrument.

We can repeatedly play the bol-s of a taal, in a plain, simple way. Playing like this is called theka. Playing theka means playing just plain bol-s of a taal, without any embellishments. In classical music, teental, with its variations like Punjabi and Sitarkhani, is the most popular taal. Some other taals played are: Ektaal, Jhaptal, Jhumra, and Tilwada. The details:

Taal # of Beats

Teental 16

Jhaptal 10

Ektal 12

Jhumra 14

Tilwada 16

 

 

There are, of course, several other taal-s and several other percussion instruments.

The percussionist, for example, a tabla player, can play a taal by way of accompaniment to a vocal or an instrumental performance. Or, he can play it as a solo performance. In the two cases, the requirements are very different. and so also the styles of performance. It is easy to follow these differences, if we frequently listen to tabla accompaniment and solo performances.

 

Some other popular taals, used commonly, are:

Name of the Taal Number of Beats

Dadra 6

Khemta 6

Roopaka 7

Keharva 8

Bhajan 8

Deepchandi 14

 

3.0 Vocal Music

 

3.1 Genres

Every vocal performance is rendition of or based on some raag. However, there are several forms or genres of Hindustani classical singing. Each of them has a distinct identity and characteristics. Each one also requires certain exclusive skills to perform. A raag can be presented in any of these styles. Some popular genres of vocal classical music are described below :

§ Dhrupad An ancient style that is often used for religious or philosophical renditions. Dhrupad singers use syllables like Om, Nom, Tom etc. to develop the raag being performed. Dhrupad singing has its own special taals which are not used in other forms of vocal music, e.g., Chautala. Pakhawaj is used as percussion instrument to accompany a dhrupad performance, and not Tabla. Gamaks are used frequently in a dhrupad performance. There are four sub-styles of dhrupad, called four banis, e.g., Dagar-bani, Gauhar-bani, etc. Dhrupad is a dying art and there are very few remaining practitioners of it.

§ Khayaal By far the most popular style of vocal classical singing in the present era. Khayaal singing involves presenting a lyrical composition in classical style. Most vocal performances these days fall in this category. Khayaal is of two kinds - chhota khayaal and bara khayaal. The former is a small composition sung at a medium or fast tempo, usually to the accompaniment of a percussion instrument. The latter is a longer rendition that allows deep exploration and gradual expansive development of the raag being performed. A typical vocal performance involves a bara khayaal follwed by a chhota khayaal in the same raag. Khayaal singing is typically accompanied by Tabla as the percussion instrument. Besides using a lyrical composition to present a raag, khayaal singing involves the various ornaments (taan, meend, etc.) using aakaar (using syllable aa for all swaras) or sargam (using consonents for the corresponding swaras, i.e., Sa, Re, Ga, Ma, Pa, Dha, Ni).

§ Tarana Tarana singing does not involve any lyrics but instead uses syllables like tana, deem, oder, dir, tadiyan, etc. A tarana performance is usually at a faster pace than Khayal or Dhrupad. The percussion instrument used to accompany taranasinging is Tabla.

§ Thumri A light classical form of singing, usually set in Deepchandi taal (14 beats). Thumri singing usually involves lyrics with sentiments of lovers, like separartion, complaint, request etc.

 

 

3.2 Stages of a typical vocal performance

A typical vocal performance includes two broad stages – aalaap followed by bandish in the same raag. Aalaap is the act of illustrating and developing the raag using aakaar and/or sargam. Aalaap doesn’t require any words or lyrics. At this stage the artist explores the swaras of the raag and gradually develops phrases and patterns. Bandish is a composition, i.e., rendition of lyrics in a raag. Bandish is usually set to a particular beat (taal). The tempo (laya) of a bandish increases gradually from slow (vilambit) to medium (madhya) to fast (drut). Very slow and very fast tempos are called ati-vilambit and ati-drut respectively.

 

4.0 Instrumental Music

 

4.1 Stages Of A Typical Instrumental Performance

A typical instrumental performance includes four broad stages – aalaap followed by jor followed by jhaala, and finally gat, in the same raag. Much like in vocal singing, Aalaap is the act of illustrating and developing the raag swar by swar, and then phrase by phrase. (To be completed…)

 

5.0 Miscellaneous Terms

 

Naad Sanskrit for sound.

Ahad Naad Asound produced artificially, e.g., by striking, plucking, blowing,etc.

Anaahad Naad The natural sound energy pervading the universe which is not audible to humanear.

Harmony Whentwo or more notes are produced simultaneously and the combination sounds agreeable and pleasant. Indian classical music does not have the concept of harmony. Western classical music does.

Melody A sequence of individual notes (not simultaneous) that sounds agreeable and pleasant. Indian classical music is melodic. Western classical music involves melody as well as harmony.

Samvaadita When two swaras are produced simultaneously and the combination sounds agreeable and pleasant, it's called samvadita(consonance). Different combinations of swaras sound agreeable to varying degrees. The consonance of Sa and Sa (of two different saptaks) is the most agreeable and pleasant (highest concord), with Sa-Pa and Sa-Ma consonances following in descending order of concord.

Tirobhaav The act of an artist constructing and dwelling on phrases or patterns of swaras technically allowed in the raag being performed but not usually performed in that raag. By emphasizing the unusual and rarely heard phrases, the artist is in a way hiding the known and popular character of the raag. Though theoritically permitted, this may result in audience not being able to identify the raag. Only well-accomplished artists, who are established authorities, usually attempt tirobhaav.

Avirbhaav The act of an artist, having done tirobhaav for a while, returning to the known and characteristic phrases or patterns of theraag being performed. Tirobhaav having confused the audience, avirbhaav immediately gives them a sense of familiarity and identification of the raag. While tirobhaav hides the usual character of araag, avirbhaav brings it out. Tirobhaav not followed by avirbhaavis not generally prescribed.

Nyaas-swar The act of halting or staying on aswarin a composition, before taking the next swar.

Upaj When starting a performance, the artist presents the notes of the raag one by one, (using aakaar or sargam). The act of repeating and emphasizing aswarat this stage is called Upaj.

Barhat When starting a performance, the artist presents the swaras of the raag (using aakaarorsargam). The act of slowly and gradually introducing the swaras one at a time while weaving and establishing characteristic patterns of the raagis called barhat. For instance, when performing raag Yaman, the artist may first dwell on only Madhya Sa and Mandra Ni. Then introduce Mandra Dha, and dwell on Sa, Ni and Dha for a while. And then introduce Madhya Re, and so on.

HEATING A BUILDING

 

A central heating system provides warmth to the whole interior of a building (or portion of a building) from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be an HVAC (heating, ventilation and air conditioning) system.

Central heating differs from local heating in that the heat generation occurs in one place, such as a furnace room in a house or a mechanical room in a large building (though not necessarily at the "central" geometric point). The most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler. The resultant heat then gets distributed: typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes. Increasingly, buildings utilize solar-powered heat sources, in which case the distribution system normally uses water circulation.

In much of the temperate climate zone, most new housing has come with central heating installed since the Second World War, at least. Such areas normally use gas heaters, district heating, or oil-fired system, often using forced-air systems. Steam-heating systems, fired by coal, oil or gas, are also used, primarily for larger buildings. Electrical heating systems occur less commonly and are practical only with low-cost electricity or when ground source heat pumps are used. Considering the combined system of central generating plant and electric resistance heating, the overall efficiency will be less than for direct use of fossil fuel for space heating.

 
 
 
 

Have you ever wondered how people centuries ago heated up their homes, or shall we say, their castles and mansions? Fireplaces were the only means of heating up draughty rooms in those days. You can just imagine the amount of firewood that was used for the past centuries! Today, heating up any structure is a breeze. There is no need to chop up firewood and waste precious trees in order to heat up homes and building.

Heating a building goes hand in hand with ventilating and air-conditioning a structure too. In the USA, HVAC (acronym for heating, ventilating and air-conditioning) is responsible for the heating system of homes and buildings. In the UK the Chartered Institute of Building Services Engineers basically takes care of the heating, ventilating and air-conditioning of buildings. For the purpose of simplification, only the heating system of HVAC will be discussed.

There are different systems of heating up a building. In colder climates, centralized heating is used to heat homes and buildings. This system calls for the use of a furnace, boiler and pump to heat up air, water or steam. The most common types are radiant, forced air, hydronic, geothermal and steam radiant.

 

 


Date: 2014-12-22; view: 1022


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