But after this high tide of prosperity there was to come a reverse. A powerful faction, that for a time had been crushed by Gluck's triumph, after a while raised their heads and organised an attack. There were second-rate composers whose scores had been laid on the shelf in the rage for the new favourite; musicians who were shocked and enraged at the difficulties of his instrumentation; wits who, having praised Gluck for a while, thought they could now find a readier field for their quills in satire; and a large section of the public who changed for no earthly reason but that they got tired of doing one thing. Therefore, the Italian Piccini was imported to be pitted against the reigning deity. The French court was broken up into hostile ranks. Marie Antoinette was Gluck's patron, but Madame Du Barry, the king's mistress, declared for Piccini. Abbé Arnaud fought for Gluck; but the witty Marmontel was the advocate of his rival. The keen-witted Du Rollet was Gluckist; but La Harpe, the eloquent, was Piccinist. So this battle-royal in art commenced and raged with virulence. The green-room was made unmusical with contentions carried out in polite Billingsgate. Gluck tore up his unfinished score in rage when he learned that his rival was to compose an opera on the same libretto. La Harpe said--"The famous Gluck may puff his own compositions, but he can't prevent them from boring us to death." Thus the wags of Paris laughed and wrangled over the musical rivals. Berton, the new director, fancied he could soften the dispute and make the two composers friends; so at a dinner-party, when they were all in their cups, he proposed that they should compose an opera jointly. This was demurred to; but it was finally arranged that they should compose an opera on the same subject. "Iphigenia in Tauris," Gluck's second "Iphigenia," produced in 1779, was such a masterpiece that his rival shut his own score in his portfolio, and kept it two years. All Paris was enraptured with this great work, and Gluck's detractors were silenced in the wave of enthusiasm which swept the public. Abbé Arnaud's opinion was the echo of the general mind--"There was but one beautiful part, and that was the whole of it." This opera may be regarded as the most perfect example of Gluck's school in making the music the full reflex of the dramatic action. While Orestes sings in the opera, "My heart is calm," the orchestra continues to paint the agitation of his thoughts. During the rehearsal the musician failed to understand the exigency and ceased playing. The composer cried out, in a rage, "Don't you see he is lying? Go on, go on; he has just killed his mother."