Bach`s Music and Church Acoustics
Transcription
Bach`s Music and Church Acoustics
Bach's Music and Church Acoustics Author(s): Hope Bagenal Reviewed work(s): Source: Music & Letters, Vol. 11, No. 2 (Apr., 1930), pp. 146-155 Published by: Oxford University Press Stable URL: http://www.jstor.org/stable/726344 . Accessed: 02/01/2013 07:23 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. . Oxford University Press is collaborating with JSTOR to digitize, preserve and extend access to Music &Letters. http://www.jstor.org This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions BACH'S MUSIC AND CHURCH ACOUSTICS IN Germany ' architecture' in the sense of Raumkunst, or the art ofenclosedspaces, is closelylinkedwithmusic. Behind the eighteenth cenituryconcertroom traditionbeginningabout 1743(l) there lies the music tlhathad as its home the Lutheran church with its peculiar acoustics. At the Reformationchanges affectingchurchacoustiesweremade in two kinds. First, German as a language took its place beside Latin in the officeof the church,and secondly,side galleries were added to the churches in addition to the west galleries already existing, so that congregatiolns were increased in proportionto air volume and thereforereverberationwas correspondinglyshortened.(2) Medieval Latin, as a language forsong, providesa beautifulseries of tones for a Gothicchurchwitha long reverberation;it has massive open vowels with the most delicate consonantdivisions; it is homogeneousin its and strength. Considerin the B minorMass the soprano refinement word unigenite and then the shout of Sanctus by the whole choir. German, on the other hand, while retaining a grand series of open vowels has in addition a great number of contrastingconsouants. Compare in the old carol the words Puer natus in Bethlehemtwith Ein kind geborn zu Bethlehem. The latter as a tone sequence is more vivid and more punctuated. All that seems harsh to English ears in the spoken German falls into focus in song or oratory; the language seems to have golden vowels and steel consonants. This is not fanciful. There is a particularsound quality that can be defined as ' carryingpower.' It has not to do with intensityor amplitude, but arises from the fact that a particular range of pitch is more andible to the human ear than the rest of the scale. Now sounds having pitch componentswithinthat range can be heard betterthan puirersounds withouitsiueh pitch components. It is this fact that causes the well-knowncarryingpower of syren noises and explains whlya staccato passage on a h-ornor reed inistrument can be heard (1) A society for secular concerts was fouindecdin Leipzig in that year. (2) Reverberation-the time taken for a sound to die away in any room after the source has ceased-can be measured in seconds. It varies inversely as the absorbing power and directlv as the air volume. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions ~ 0 u CL 10 ~ (24 u 6 m~ ~ ~ ~ 0 -~~~~~~~~~~~~~~~~~~~~C ~ ~~~~0(/ -lz~~~~~~~ 0~~~~~~~~~~~~~~~~~~0 This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions LEI PZIG THOMA3KJIKCHE . ,FT. MERS 0 24 02 2 _ r I - FE?ET 5 0o, 1 o A 5 to l l 5 10 20 _ _ a~~~~~~~~~I I I.___.X S EC T IO N C R CD 5 5 METR-ES 7 MH 30) 20 15 40 SQ 60 2. 10 80 I929. Fig 2. Leipzig. ThomaskircheCrossSection showingWest Galleryas existing. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions S~~~~~~~~~~~~~~~~~~~~~~~~~~~~...... 77| i W0riE Fi3 g~~ Lepig 00~~~~~~~~~~~~~~~~~20 |l Vie of th Thmskrh fo th Not West. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions beforethe Fig. 4. Leipzig. Interiorview of the Thornaskirche alterationsin 1877. (Afteran engravingin the Stadtmuseum.) This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions BACH'S MUSIC AND CHURCH ACOUSTICS 147 moreclearlyin a cathedralthanthe same passageon strings. It is quite possibleto imparta reed tone to the voice,as in the case of the Vaticanchoir,and such a tone increasesthe audibilityof the The effectof directsound besidescausinga less reverberation.(3) the Germanz and sch soundsis something similar;notonlydo they voweltones carrythe sense in a largebuildingbut theyalso modify and influence whatByrdcalls ' thelifeofthewords.' Thustheyhave considerableinstrumental value and must have contributed to the development of oratorioand cantatain the church. But Latin was not supersededin the Lutheranchurchservices. Luther,unlikeKnox and Cranmer,was a musician,and preserved much of the Holy Officein Latin, namely,Kyrieand Gloria,the Credo,the Horae and Magnificat.'Latin ' and ' Music' werethe twoimportant subjectstaughtin theschools. Latinwas thelanguage of mannersand of publicaddress,and the monumental Latinityof theGermaneducatedclassescan be seen, wellon intothe eighteenth and century,in Bach's own letters. This meantthat congregation in churchto bothsetsofvoweltones-the musicianswereaccustomed Germanand theLatin-and also thatchoralworkswerecomposedin both. Bach wrotecomparatively littleto Latin wordsas compared to German,but thatlittlecontainsthe B minorMass in whichthe greatLatin choraltradition of the MiddleAges seemsto culminate. In Bach's workand in St. Thomas'Churchthe Latin Mass and the Germancantataexistedfora whileside by side. But the dramatic valueofGermanand also thewholedevelopment oforchestral instrumentstendedto reinforce the cantata and oratorio. Orchestral instruments had invadedthe Germanchurchprobablywiththe early Gospelor new stylemotetmusic,but owingto acousticcauses they wereable to remainthereand taketheirplacein a rapidco-operative thatculminated in the westgalleryof the Thomaskirche development underBach. The orchestral introduction to thecantatawas probably theearliestpurelyorchestral composition.(4) But in thechorusesand hymnsthe instruments were not mere accompaniments to voices: theyweretruepartsand had to be hearddistinctly.The character of Bach's compositions as worksofart lies in a close thematicintercoursebetweenvoicesand instruments.In his doublechoruseswith instrumental accompaniment each voice has a melody,each chorus is completein itself,the instrumental parts togetherforma unit and thewholeis a grandharmony. (3) A less reverberationis caused because high pitch-components are relativelymoreabsorbedby ordinarywall surfacesthan are low pitch-components; this is shownby the Sabine curves. (4) Bitter. Life of Bach. Abridged translation by J. Kaye Shuttleworth (1873). p. 45. Vol.XI. D This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions 148 MUSIC AND LETTERS weredevelopingtechnically and werethe object Also instruments makers of attention.Mastermusicianswereoftenskilledinstrument and builders. As an instanceofthisI can onlymentionhereBach's in organbuildingand organspecification, ownpracticalcraftsmanship and his designing of newinstruments such as his viola pomposaand ofthisis thatinstrument luteclavicembalo.The significance makers, some of room especiallyorganbuilders,inevitably acquire knowledge in thisrespect. On a acoustics,and Bach himselfhad a reputation visitto the BerlinOperaHouse in 1747 he is said to have remarked its effects. uponthewhispering galleryofthesalon and foretold That Bach was sensitiveto acousticsis also suggestedby Dr. SanfordTerryas a reasonforhis strongpreference forthe Thomasto theNicolaikirche.(5) musicin each kircheas compared He conducted on alternateSundaysovera periodof twenty-seven yearsand wrote roughlya new cantataeverymonth. Bach ' composedat least 265 '(6) More Cantatasduringthe twenty-seven yearsof his Cantorship. significant still,Dr. Terryis of opinionthatmostof,perhapsall of, his largeworkswerecomposedforproduction at St. Thomas'. The reactionofthechurchas an instrument uponthecomposer is obvious and moreespeciallyso whenwe remember thattheworksforthemost part were performed as soon as written. was St. Thomas'? Whatkindofbuildingtherefore The charchhas considerable character. It is as largeas a small cathedral. The plan and sectionare givenin figs.1 and 2, and views in figs.3 and4. The acousticanalysisis givenat theendofthearticle. The churchis a late Gothic,threeaisled building,of Augustinian withlevel vaults,no transepts,and a narrowaltar piece foundation or -chancelset not in the same straightline as the nave. It was dedicatedin 1496 and in 1539was takenoverby the Reformers, who removedchoirscreenand side altarsand madeofit a parishchurch underthe LeipzigMunicipality.Engravingsof the middlesixteenth muchas it is to-dayand the shell of the centuryshowit externally church,withthemajorinterior dimensions, has remainedunchanged, givingan air volumeof some640,000cubicfeet. The vaultingunder the galleriessuggeststhatthe churchwas originally plannedwitha westgallerywhichwas prolonged one bay downeach aisle.(7) This is likely,since a west galleryin Germanchurchesgoes back into medieval times and may have developednaturallyout of the (5) The latter was a smaller building with a cramped organ gallery on the south aisle, and from an executant point of view, though not necessarily from a hearer's point of view, would certainly have been less satisfactory. (6) Terry. e. S. Bach: a Biography. p. 177. (7) See Gurlitt, C. Ba?, und Kunstdenkmalerdes Konigreichs Sachsen, Leipzig. Vol. I, p. 45. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions BACH'S MUSIC AND CHURCH ACOUSTICS 149 Romanesquetribunegallerieswhichare occasionallyfoundat the west end. The existinggalleryfronts,however,bothon the west and all along the sides, are of an earlyRenaissance'designin red sandstonedatingfromtheendofthesixteenth century.In 1707there werefurther alterationsand yet moregallerieswere builttogether withsmallboxesand numerousstaircases. A drawingin the church archivesshows at the westend twotiersof galleries-theupperone holdingthe choirand organ,the lowerused evidentlyas a kindof loge. Abovethe existingside galleriesthe same drawingshowsan usedforprivateboxes. An interior uppertier. Thistierwas probably viewin theStadtmuseum (fig.4) showsthenumerous privateboxesor furnishedand 'swallows' nests.' These boxes were comfortably withinthemon highfestivals important Hofrathsand Biirgermeisters -connoisseursin Passion music-reclinedat theirease behindcurtainsthatcouldbe slightlydrawnso as just not to hide the crowds below.(8) From these ' nests ' also various members of the school councilkepta criticaleye on the boys of the Thomaschulein the galleryand on old Bach risingfromthe clavierforthe choruseswith a tightroll of musicforbaton. The encroachment of galleriesand boxesin thiswaywas due to the Lutheransystemof churchgovernmentwhichplacedthe churchunderthe towncouncil. But it also ofthechurchas a building, and showedtheimportance and popularity thatit createdthe acousticconditions we mustremember thatmade ofcantataand Passion. possibletheseventeenth century development The buildingbecame,in fact,a kindof religiousoperahouse. In Bach's timethegalleryat theeast endofthenaveheldan extraorgan. The ' swallows'nests' anduppertierofsideboxesweresweptawayin of west galleryand 1877, at whichtime the presentarrangement organwas made. But the seatingin Bach's timewouldhave been less dense,anidreverberation wouldhave beenonlyslightlyless with a fullcongregation than at present. The reverberation figurefora of 1,800 underpresentconditions festivalcongregation worksout at 2- seconds. Thisfigurerepresents acoustically a compromise between cathedraland concertroomconditions. An EnglishGothicchurch of this size wouldhave some four or five seconds reverberation, whereasa concerthall seating1,800 wouldprobablyhave not more than 1-1seconds. At St. Thomas' also the sourceof soundis well placed. The positionof the choirand orchestrain the westgallery enablesthemto makeuse ofthelevelvauiltas a reflector, and toneis, in fact,directeddownon the congregation withoutnoticeableecho paths. In Bach's timethe choirwereslightly higher. A thirdpoint is thelargeamountofresonantwoodarea present,as muchas 15,200 (8) Good examples of these boxKesstill surviving can he seen in the towp church at Weimar. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions 150 MUSIC AND LETTERS squarefeet. Fourthly,the churchhas no ' note' or fixedtonality. The noteofa largechurch-generally trebleA-gives a preference to worksin the key of A and makes unaccompanied singingin any other key more difficult. The ' recitingnote ' or ' Collect note ' in any largechurchis generallytrebleA or A flatforthe same reason, and thisfacthas profoundly influenced medievalmusic. But in the Thomaskirche there seems to be no special regionof' response,' probably due to theunicellular nave,theabsenceoftransepts, and to the comparatively shortreverberation.And we findthat Bach was notrestricted, butwrotehis worksin all kindsofkeys. Alsohe was able, owingto the moderatereverberation of the Lutheranchurchor chapel,to writefuguesforthe organwithrapidbass parts. Many of the fugues,owingto theirtempo, are lost in cathedrals,the bass partsbecomingnothingbut a confused roaring. If Bach had had to play in King's CollegeChapel,Cambridge, insteadof in a Lutheran building,he wouldnot have composedfugueswithsuch parts. But thoughexact phrasingis possiblein St. Thomas', the full singing tone of voices is not sacrificed.On any Friday or Saturdaythe visitormay hear the boys of the Thomasschule singingmotetsand Latin psalmsbyPalestrinaand Vittoria. HavingnotedthesethingsI attendedthe bicentenary performance of the ' St. Matthew' Passion music with interest. The ordinary festivalarrangements of the churchwerefollowed.The chancelwas filledwithseats facingwest. Carpetswerelaid on gangways. The totalcongregation was about 1,800. The gallerycontaineda choir of 150 and orchestra of 60-far in excessof the forcesemployedby Bach. The continuo was taken on the organ and the recitative accompaniments on a largeharpsichord.The performance underDr. Straubewas a revelationof tone fulland powerful, but highlydis-. ciplined.The soloistshad notto strain. The orchestra, thoughlarge, was groupedand trainedforits parts,and the parts ' were heard like silkenthreads'; the toneof stringsspeciallybenefited fromthe largewoodarea. Stringsandvoiceswerecomplementary and thusthe truearchitectonic designof the musicwas instantly perceived. Also therewas no dragging.The newGermanchurchtempo,the fruitof an intelligent was obviousand one recalledthosewords scholarship, in the Bach necrology' he was veryaccurate,and extremely sure in the tempo whichhe generallytookverybriskly.'(9)By the congregationseated in the nave facingeast the choirwas not seen; the high piers and fineproportions of the churchalone presented themselves, and at timesmusicand architecture combinedto reveal the geniusofpurestructure. (9) As quoted by Schweitzerin J. S. Bach. Vol. I, p. 210. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions BACH'S MUSIC AND CHURCH ACOUSTICS 151 St. Thomasis in facta homeforthemusic,and thisis soonrealised whenwe tryin England to finda suitableauditoryeitherforthe B minor Mass or the ' Matthew' Passion music. The concert hall performance withitsHandeliantechniquehas obviousdisadvantagesthe massedinstruments have firstto make themselves heardagainst the chorusand the chorusmustshout againstits own absorption. Yet a small choir and small orchestrain a crowdedconcert hall will not give the body of tone required. On the other hand,in a cathedral navehavinga longreverberation althoughchoral toneis enhanced,stringsat ordinary tempoare onlyarticulatein the upper registers,'cellos and double basses are almost inaudible, staccatopassagesrun together, brass is generallyfar too loud, and male soloistssound harsh. That this is not more recognisedby musiciansis due to the factthatconductors situatednear theirsound sourceget enoughdirectsoundto steerby. But it is far otherwise to listenersin the body of the church. Thus, at the Canterbury festivalin August,1929,a velariumhungoverthe orchestra reduced reverberation locallyto a pointsuitablefora microphone pick-up,but theObserver critic(Mr. A. H. Fox Strangways) reported as follows Reverberationblurredall orchestraleffects . . . the difficulty arose with any sort of filigree. Elgar's " Enigma Variations" and Bach's tripartile stringsin thethirdBrandenburg weremostlychaos.' a real problemin acoustics The Bach CantataClub had therefore when they had to choose an auditoriumand in St. Margaret's, Westminster, whetherby accidentor design,theyfoundthe satiswhich factory compromise betweenchurchand concerthall conditions we have alreadyreferred to. St. Margaret's,a perpendicular churchwith wood ceilingsand without transepts, has had an acoustichistory eventful as St. Thomas'. It, too,was re-formed not longafterit was completed and its painted screenand altarsweretorndown. Its wallshave heardLatin Mass, AnglicanLiturgyand Independent sermon. As chapelextraordinary it was a goodpreaching to theHouse ofCommons placeand thescene ofDr. Usher'ssermons. It receivedfromWrenin 1681 an enormous an apse at centrally placedpulpitand galleries.(10?)It had originally theeast end. In theeighteenth century organand choirwereplaced in a westerngallery,butin the nineteenth centuryall gallerieswere sweptawayand thechurchwas restoredby Gothicscholarsnearlyto itsmedievalform. a marked' note,'has a verylargewoodarea and with It is without a fullcongregation of just undertwo of 1,000 givesa reverberation seconds. The analysis in table formis given on p. 155. Both (10)Westlake'sSt. Margaret's, Westmin,ster. p-.68. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions 152 MUSIC AND LETTERS St. Margaret'sand St. Thomas'have woodfloorsto thepewswithair spacebeneathgivinghighlyresonantareas. The success of the churchwas clearly shown at the English of the ' St. Matthew' Passion performed bicentenary performance by the Club on November27th, 1929, underMr. KennedyScott. Comparing the twoperformances--the Englishand the German-in retrospect,each so scholarly,one is consciousnot only of two of the structure techniquesbut also of twointerpretations of Bach's music,oftwolanguageswiththeirunderlying vowelscales each with a different and modifying emotionalcontent, both,twochurchforms, each with its roots in a rich but distinctmedievalculture. The CantataClubhad limitedits forcesto littlemorethanthoseoriginally used by Bach. Mr. KennedyScottemployedaboutthirty-five voices and twenty-seven instruments, includinga harpsichord, and had this couldmakethemselves advantagethatthe instruments heardwithout any effort againstthe voices;each instrument had to be as a soloist and the delicacyand incorporation oftheperformers in the dexterous counterpoint wasobvious. Alsothechoirundertheacousticconditions of St. Margaret's had the ' fullness' though not the ' strength' of toneofthelargerGermanchoir,and thiswas helpednotonlyby the rightreverberation but by the longersound path to the roofand downagain, whichis givenby a floorpositionof the choir. The beautifulcantabiletonebothof soloistsand choruswas achievedby makinguse of the churchas an instrument.Thus the choralesat St. Margaret's,unaccompanied, and sungwithcontemplation, had a beautyof escape,and wereunlikethe Germanchoraleswhichcame likegreatorganicbeatsin the structure of the drama. On theother hand,at St. Thomas'theGermanchoirpositionon a western gallery, withits tone deliveryfromthe vault,gave an advantagein attack. There was nothingin St. Margaret'sso shattering as the German renderingof ' Loose Him! Leave Him! Bind Him not! ' and of the musicthatfollowswithits orderedinstrumental conflict and shouting ofgargoyles as thougha Gothicroofhad comealive. Andthisintense Germanqualitywas madepossiblebythelanguage. Bach is supreme in his use bothof the vowelscale underlying the musicand of the Germanconsonants.Justas Miltonin Englishversecan penetrating takea wordand summonintoit a wholeworldof experience, so can Bach whenhe breathesthe wordbeteor singsSchmerzen. Without thisfirstmusicof the languagethe Englishversionwas cold and by comparisoncolourless. But this was inevitable. And this very elimination lefta marvellously clearmusicalprofile-auniversality of artisticeffect. Thus in moreways than one the Englishwas the rendering ofthesanctuary withitsfewconsecrated voices,theGerman the rendering ofthe nave withits breathas ofthe people. We have This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions BACH'S MUSIC AND CHURCH ACOUSTICS 153 seen indeedthatthe massesby invadingthe Germanchurchcreated the toneconditions underwhichsuch musicwas made possible,and in Germany thepeople,whether silentorquietlyfollowing thechorales, seema partofthe performance, whilethe musicis knownintimately to a verygreatnumber. At St. Margaret'swe werelistenersonly, in a churchrestored to itsmedievalforms,and attentive to oursingers whoweremakinguse oftheoriginalacousticconditions muchas they had beenmadeuse ofin medievaltimes. In bothit was madeevident thatin such suprememusicalworkspersonalChristianity is likelyto be preserved moresafelyagainstattackthanformerly behindthewalls ofmonastic fortresses. HoPE BAGENAL. Reprinted throughthe courtesyof the editor of the Journal of the Royal Irnstituteof British Architects. This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions MUSIC AND LETTERS 154 LEIPZIG THOMASKIRCHE TABLE REVERBERATION Volume 640,000 cu. ft. Seating, 1,800 (Congregation). Cube per seat, 355 cu. ft. Absorbent. ________ ________ Are oer Remarks. ________ Sq. ft. _______ C 0 025 Plaster on rubble, Lime plaster dis- 38,000 stone walls and tempered brick vaults 4,000 S t o n e g a e r y Red sandstone, porous piers __slightly frontsand _____ _____ _________ __ _________ Marble floor to Sanctuary to Window glass in Responds lead and iron middle pitch frames Wood panelling in Oak. Responds a i sl e s and to low middle 1,500 UNo.oAdjument nits Ad u t e . efficient, | N Not.o 950 (Adjustments madein the 950 120 Add 10% for breaksand 132 separateItems] 0 03 _______mouldings . 15 15 0 01 3,400 0-027 3,000 0-1 1,900 0<1 190 Wood floors to Airspace 1 ft.under 5,100 deal boards.High pew areas middle pitch.Very 01 510 Less 10% for 459 shading Wood floors to Responds to high middle pitch galleries Lino.on remainder No undermat gangways Carpeting, nave Exposed and Sanctuary No undermat Wood pew ends Oak varnished and exposed desks in Heavy tapestry Curtains Sanctuary in Thick wool Curtains galleries a n d over nave door Brocade p a n e 1s and canvases in Sanctuary chamber Wood and pipes Organ and opening Pew seats in nave Largedeal tip-upsIn pews. and galleries nave.Gallery Cane chairs. No plufew fe chairs chirs 5,200 01 4,000 0 04 520 Less 10% for 468 shading 160 160 520 0o15 78 78 2,000 0-06 120 120 0,2 78 78 0 15 150 t 150 pitch Sanctuary . . W o o d panelling Oak. Responds in galleries to high middle 1,147 918 Add 25% for transmission 300 300 ._ .. 190 pitch resonant plus _ 390 1,000 840 01 84 84 550 0-08 44 44 484 484 1,613 Average 0 3 per cushions seating ABSORPTION TOTAL PERMANENT Full congregatlon On pews and 7,920 1,800 4*7 less 0'3~4'4 seats as above per _______ ______ ___ ___ ______ ______person One-third congre- On pews and seats as above gation ____________________ Choir & orchestralNeglect seats t_ - _ _ _ _ _ 600 4*7 less 2,640 0p3e4r4 per ~~~person 987 I 210 4-7 (Full congregation (1,800) .. One third congregation (600) Rehearsal (210) .5.8 Empty. .t 25 seconds. 4.3 66 This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions 4,859 7,920 .. .. _ _ _ _ _ _ _ 2,640 987 BACH'S MUSIC AND CHURCH ACOUSTICS ST. MARGARET'S, REVERBERATION Volume 257,000 cu. ft. 155 WESTMINSTER TABLE Average seating, 1,000. Cube per seat, 257 cu. ft. Net Areaor CoNo. of Remarks. Number Absorbent. Adjustment| No. of Units. efficient. ft. Sq. Ano.o 0 03 327 Plus 5%.for Masonry. Rag- Friable and 10,900 343 sto ne n o t slightly porous sfouumen plastered etc. Stone an d tile flooring in l e a d Responds to Glass panes middle tones 2,600 0-02 4,000 0-027 to Glass panes in Responds choir screens middle a n d _ middle high 112 0-027 Wood ceilings _ 0-06 7,250 300 to Woodpanelling in Responds 0-1 chancel middle tones Wood pew floor- Responds to low 0-06 4,620 middle tones ing Elm pews. Back Responds 0-06 to 5,250 and end panels middle tones sq. ft. 02 Elm pew seatings With a number 1,000 of seat mats seats per seat 05 Hassocks 10 x 15 x 5 in. No. 1,000 each Organ case Wood and pipes 504 0-08 Curtains. Flags. 250 Average Altar carpet 0-12 l TOTAL PERMANENT Choir 30 1 Congregation full Coeff.4 7-0-2 1,000 Congregation,one- Coeff.4 7-0-2 third =4-51 330 52 52 108 Add 25% for transmission 3 135 435 30 435 30 277 Less 10% for shading 315 250 200 200 i00 Less 10% for shading 50 30 t. - 315 450 50 30 ABSORPTION 47 141 4-5 4,500 2,293 141 4,500 45 1,500 1,500 . Congregation, full . ongregation, one-thir'd " Rehearsal .. ' Empty. ' Reverberation 3 v = - 19 3-3 53 5-6 - x 0 05. t is the period of reverberation after the sound source has ceased, A measured in seconds; V is the air volume of the hall included within its bounding surfaces in cu. ft.; A is the total number of units of absorption provided by all the surfaces and objects in the buildings as set out in detail in the tables; the figure 0.06 is the Sabine constant for buildings measured in foot units. t This content downloaded on Wed, 2 Jan 2013 07:23:58 AM All use subject to JSTOR Terms and Conditions