Benjamin Britten reigns on opera stages of N. America; ENO presents a glorious 'Gloriana' in New York; Canadian Opera falters with 'Death in Venice' in Toronto

This seems to be the year of Benjamin Britten. Covent Garden at the Los Angeles Olympic Arts Festival, the Opera Theatre of St. Louis, the Toronto Arts Festival, the Metropolitan Opera, the English National Opera (ENO) - all have presented (or will be presenting) Britten operas on these shores in '84.

Of all of Britten's established operas, ''Gloriana'' has remained the enigma, particularly on this side of the Atlantic. Commissioned to celebrate the coronation of Queen Elizabeth II, it proved a colossal flop at its world premiere at Covent Garden in 1953. The gala audience could not have cared less about anything on stage. The impressions of that dour first night have beset the opera ever since. Sadler's Wells (now ENO) revived it in '66, and several times thereafter.

Yet ''Gloriana'' is a grand creation, now a pageant, then a spectacle, but almost always a human drama. The libretto, by William Plomer, deals with the familiar story of Queen Elizabeth I and Robert Devereux, Earl of Essex. It sensitively and touchingly focuses on the Queen's dilemma - should her heart or her love of England rule her actions?

Perhaps its general lack of glorious public scenes disappointed the opening-night gathering. Despite the Norwich scene, with its elegant choral work and superior dance music, this is a private, not a public, piece, and autumnal in tone. Among the particularly strong moments in the work is the prayer that closes the first act: Elizabeth implores God to help her in her time of personal crisis in a profoundly moving and superbly theatrical prayer.

Her last duet with Essex is emotionally shattering, and the scene in which she signs the death warrant, gripping. Controversy has surrounded the closing moments of the opera, where Elizabeth flashes forward to her death, the curtain dropping on a spotlighted monarch while the offstage chorus sings - a cappella - the pivotal theme of the opera. Certainly as recently performed by ENO at the Metropolitan Opera House in New York, it made for a devastatingly effective finale.

The English National Opera is not noted for its singers, but rather for its singing actors, and its tangible sense of ensemble work. This production, directed by Colin Graham, is a jewel, a vital testament to the strengths of the company. The simple production gave the semblance of lavishness. The clean, unfussy staging allowed the drama to unfold with focus on the characters rather than on the costumes. With the chorus, one sensed a real population rather than a faceless singing mass.

The finest singing of the production came from Arthur Davies as Essex. His voice is clear and full, his diction first-rate, and his acting ability emphatically untenorish. There were strong assisting performances from Elizabeth Vaughan (Lady Penelope Rich), Alan Opie (Sir Robert Cecil), and Neil Howlett (Mountjoy). Noel Davies conducted with care, highlighting the restraint in the orchestral writing without once shirking or misgauging the crucial climaxes.

Still, the performance sat squarely on the shoulders of Sarah Walker's riveting Queen. The mezzo sings a soprano role. In the upper stretches of the music one wished for a fuller, more secure instrument to make the musical/dramatic points. But her stage demeanor, her startlingly fine diction, and her ability to hold the focus without swamping the rest of the cast were all marks of a remarkable actress. She clearly felt the depths of this role in every fiber of her being.

Would that this sort of attention to detail and the spirit of a work had marked the Canadian Opera Company's recent production of ''Death in Venice.'' This was meant to be the centerpiece of an ambitious music festival celebrating Toronto's 150th year. Unfortunately, director (and company head) Lotfi Mansouri had little sense of the evanescent quality of this final operatic testament. Britten has hauntingly set Thomas Mann's tale of a German novelist who has spent his life writing about ideal beauty, only to find it embodied by a young Polish boy in Venice. The ensuing emotional and psychological crisis shatters and finally destroys the author.

It is a piece that works best in small theaters, yet here it was on the stage of the cavernous O'Keefe Center in Toronto, where everything has to be amplified. In the central role of Gustav von Aschenbach Mr. Mansouri cast a tenor, Kenneth Riegel, whose diction was alarmingly unintelligible. Then he cast Allan Monk - an accomplished baritone with an unfortunately stolid stage presence - as the various ominous, mercurial nemeses that guide Aschenbach on his downward spiral.

Wolfram Skalicki's mirrors-and-projections set gave a ponderous, ill-fitting frame for Britten's dream world drama of ideals, impressions, and implications, which even Susan Benson's elegant costumes could not alleviate. In short, the delicate, ethereal fabric of the orchestral writing was nowhere reflected on the stage, either in setting or direction. But clearly a good deal of money went into this affair - too much, one surmises, for its own good.