Beginning tonight Auber's "Fra Diavolo" will be given with a stunning "Castle Square Production." With music sparkling, melodic and dramatic, the dialogue exuberant in fun and satire, it is not surprising that this has entrenched itself as one of the very best of comic operas. It was a stock opera with such companies as the Boston Ideals and Emma Abbott's. It was last sung in Boston, as a grand production, by the Mapleson company. The Baker Opera Company, with William Wolff, gave its last performance here two years ago at the Bowdoin Square Theatre. The hero, Fra Diavolo, is a brigand, who is discovered in the first scene personating the Marquis of San Marco, in which disguise he has been tracking the course of an English traveller and his lady, Lord Rocbury and Lady Pamela (Anglice, Lord and Lady Allcash) on a tasteful blending of business and pleasure, his object being to rob both parties of their cash and valuables, and to take my Lord's place in the affections of my Lady. Lady Allcash is bland and buxom, wormwood to her husband and honey to everyone else - is another ideal of the French school of romance. The real heroine of the drama is Zerlina, the true hearted and pure minded daughter of an innkeeper, the beloved of Lorenzo, the captain of a troup of Carabiniers, who, however, has every prospect of being rejected by her father, on the score of his poverty, till he acquires both wealth and glory by the capture of Fra Diavolo, the bandit Marquis and his lawless retainers. There are two subordinate Canditti - though far from subordinate in the interest they impart to the drama - Beppo and Giacomo, Beppo a half bully, half coward, who would stab an innocent girl, yet crawl on his knees at the mention of the Holy Virgin.