OP AT A 



concretionary form, and is opaque 

 grey. The common opal, which is 

 not opalescent, occurs in a variety 

 of colours from white to brown. 

 See Gems, colour plate. 



Opata. American Indian tribal 

 division of Piman stock, in Sonora, 

 Mexico. Embracing the Eudeva, 

 Jova, and Teguima sub-tribes, they 

 were more submissive than the 

 Pima, and are now so thoroughly 

 merged in the Spanish stock that 

 in 1910 only 43 were separately 

 enumerated. See Sonoran. 



Open Door. Term used in 

 economics as a synonym for free 

 trade. See Free Trade; Protection. 



Open Hearth Process. Method 

 of making mild steel, due to Sir 

 William Siemens, and frequently 

 described as the Siemens process. It 

 is distinguished from the Bessemer 

 process by being carried out in a 

 reverberatory furnace, and by the 

 fact that the decarburation of the 

 molten metal is effected, not by 

 burning out the carbon by a blast 



5850 



of air, but by adding fresh ore, 

 ferric oxide, in such quantity as 

 will, by the chemical reactions set 

 up in the furnace, bring about the 

 desired reduction of the carbon 

 and the purification of the whole 

 mass to the required degree. The 

 ore is usually Spanish haematite, 

 and in any case must be free from 

 sulphur and phosphorus, and as 

 free as possible from silica. See 

 Bessemer Process ; Metallurgy. 



Open Sesame. In the story of 

 Ali Baba in The Arabian Nights' 

 Entertainments (q.v.), magic 

 words that caused the opening of 

 the door of the cave in which the 

 Forty Thieves kept their plunder. 



Openshaw. District on the 

 S.E. of Manchester. A busy manu- 

 facturing area, it makes rly. rolling 

 stock, has iron-foundries, dyeing 

 and chemical works, cotton fac- 

 tories, and engineering establish- 

 ments, and is traversed by the 

 Manchester and Stockport Canal. 

 See Manchester. 



OPERA: THREE CENTURIES OF GROWTH 



J. Percy Baker, Mus.B., F.R.A.M. 



Supplementary to this article are articles on the great composers of 

 opera, e.g. Gluck; Handel; Wagner. See Acting ; Drama; Har- 

 mony ; Music ; Singing ; also Covent Garden ; Scala 



Opera (Ital. shortened from 

 opera in musica, a musical work) 

 is a hybrid form compounded 

 of music and drama, each of 

 which necessarily modifies the 

 other. The dialogue is mostly 

 in verse and sung to orchestral ac- 

 companiment ; lyrics are an im- 

 portant element, and a ballet is 

 often included. 



The rise of opera began about 

 1 582, though other forms of musical 

 drama existed before. The spirit of 

 the Renaissance rebelled against 

 the application of the contrapuntal 

 music then in vogue to the emo- 

 tions of the stage, and a little 

 group of enthusiasts, who were in 

 the habit of meeting to discuss 

 art at the house of Giovanni Bardi, 

 Conte di Vernio, in Florence, set 

 themselves the task of reviving, 

 as they thought, musical declama- 

 tion as it had been used in 

 Greek tragedy. In the hands of 

 Claudio Monteverde, an accom- 

 plished musician and a man of 

 original genius, opera began to be 

 a vehicle of increased dramatic ex- 

 pression ; but it was not until the 

 first public opera-house was opened 

 at Venice in 1637 that it advanced 

 from being the pastime of princes 

 to becoming a popular passion. 



Cavalli made use of a more 

 melodic style than was consonant 

 with the austere tenets of the 

 Bardi group, and thus initiated 

 the introduction of the aria in 

 relief to declamation or recitative. 

 i 



Melody was carried further by 

 Alessandro Scarlatti, who not only 

 established the aria as a legitimate 

 form of expressing soliloquy, but 

 also adopted two distinct kinds of 

 recitative: (1) Recitativo secco, in 

 which the voice was supported by 

 simple chords filled in at the harp- 

 sichord from a figured bass, and 

 (2) Recitativo stromento, the or- 

 chestral accompaniment of which 

 was as important as that of the 

 aria. This last, which Scarlatti 

 used when the dramatic situation 

 called for strong or impassioned 

 treatment, has been enormously 

 developed until it is now the back- 

 bone of modern opera. 



Early opera in France owes much 

 to the Italian Lulli, who possessed 

 an extraordinary faculty of adapta- 

 tion to the racial characteristics of 

 the people among whom he 

 passed his life. With him the in- 

 strumental part was better planned 

 and more highly wrought, while, in 

 addition, he obtained that justness 

 of rhetorical expression so desider- 

 ated by the French. 



German Opera 



In Germany Reiser produced 

 a large number of operas, truly 

 German in style, at Hamburg, and 

 really laid the foundations of that 

 art which culminated both artistic- 

 ally and technically in Richard 

 Wagner. In England the outstand- 

 ing name is that of Henry Purcell, 

 who composed in all 42 works for 

 the stage, several of them, full 



OPERA 



operas. As with Lulli in France, 

 PurcelPs verbal declamation was 

 nearly always beyond reproach. 



Handel's genius was so over- 

 powering, his force of character 

 so tremendous, that his operatic 

 ventures in London, though finan- 

 cially they ruined him, over- 

 shadowed all native art. English 

 opera, however, though obscured, 

 was never wholly destroyed, and it 

 managed to struggle on with a 

 varying degree of vitality until in 

 the last half of the 19th century 

 it to some extent reasserted 

 itself. In so-called " grand opera," 

 not many British works hold the 

 stage, despite their intrinsic merit, 

 because of the reluctance of the 

 British public to support native 

 art, but in light opera the works of 

 Sullivan still make their appeal. 

 Debased Forms 



The aspirations of Peri and Cac- 

 cini after a more perfect expres- 

 sion of the text, and of their suc- 

 cessors after a more perfect ex- 

 pression of the dramatic action, 

 had become lost sight of by the 

 18th century, in the ever-growing 

 desire to please the public and to 

 gratify the vanity of singers. Mere- 

 tricious stage effects were over- 

 elaborated, the different nationali- 

 ties of performers often led to the 

 use of more than one language in 

 the course of representation, and 

 the necessity for providing each 

 of the singers with opportunities 

 for personal display compelled the 

 composer to produce a certain 

 number of arias, all in the same da 

 capo form, though they fell into 

 one or other of five categories ac- 

 cording to their character. The 

 very number of the singers was im- 

 mutably prescribed, viz. three 

 women and three (or, at most, four) 

 men, the first of the latter being 

 an artificial soprano, the second 

 an artificial soprano or contralto, 

 the third a tenor, and the fourth, if 

 any, a bass, though sometimes all 

 the men were castrati. The effect 

 on librettists and composers was 

 inevitably lamentable, but the 

 public loved to have it so, despite 

 the efforts made by Handel and 

 others to break away from them. 



To Gluck we owe that reform 

 of opera which opened the door 

 to modern developments. The 

 ridiculous conventions and re- 

 strictions connected with opera 

 offended his sense of artistic fit- 

 ness, and for years he patiently 

 applied himself to study with 

 the object of ascertaining the best 

 method of carrying out a radical 

 alteration. His theories first found 

 exemplification and justification 

 in Orfeo ed Euridice, produced 

 at Vienna in 1762, in which both 

 librettist and composer displayed 



