Clara O’Brien in the title roll was a stroke of fortune. She provided the musical high points with her brilliant, technically perfect commanding voice and her stage presence made her yet again the audience’s favorite. Stuttgarter Zeitung
Clara O’Brien perfectly filled out the title role. Casting her as “the most beautiful women in the world” was a truly a first-class choice. Also her exquisite, clarion, brilliantly resounding voice was like being bathed in beautiful light. Badische Neueste Nachrichten
With the change from mezzo to soprano [sic.], Clara O’Brien was a moving and, particularly in the last scene, an erotically attractive Hélène. Pforzheimer Zeitung
The title role was wonderfully cast with Clara O’Brien, who with seductive charm and comic turns offered a delightful portrait of the potentially dangerous role of the suffering Hélène, “the most beautiful woman in the world”. In the same vein, she sang with similar refinement and sensitivity. Die Rheinpfalz
She sang and played the part ideally and was justifiably the celebrated star of the evening. Sender Frei Berlin
As the Composer, Clara O’Brien provided ideal material, from the well-supported lows to the radiant and securely mastered highs that left no wish unfulfilled. Das Opernglas
Clara O’Brien... not only impressive in her stage presence, the mezzo-soprano also displayed tremendous musical contour through a remarkably cultured voice and consistently smooth phrasing. Opernwelt
Clara O’Brien filled the role of the Composer completely with her refined manly-gestured characterization and her passionate desperation which made her a worthy interpreter of Strauss and von Hoffmanstahl. Badische Neueste Nachrichten
Octavian in Der Rosenkavalier
Clara O’Brien as Octavian... melded her voice wonderfully [with that of the Sophie] in the Rosenüberreichung scene. Badische Neueste Nachrichten
Musetta in La Bohème
The question is whether this mezzo-soprano has become a soprano. Certainly she is capable of it, for she handled the [soprano] tessitura very well indeed. She was as beautifully successful with the waltz “Quando men vo’” as with the many well-declaimed parlando passages.
...her success is due in equal parts to her convincing vocal performance as well as her fabulous stage presence. The strength of these trump cards showed themselves clearly in her Carilda. Opernwelt
With an easy and agile coloratura Clara O’Brien as Melsssa was the perfect Handel singer, especially in the vividly characterized death scene. Die Rheinpfaltz Zeitung
Clara O’Brien was a capricious Irene with sprightly mezzo timbre. Frankfurter Allgemeine Zeitung
Clara O’Brien dramatically intensified [with her] ... very malleable portrayal of revenge and anger... remarkable intensity. Badische Neueste Nachrichten
Clara O’Brien delivered the dramatic highpoint. The mezzo soprano not only presented a multi-faceted portrayal of rage and revenge but remarkable intensity. Badische Neueste Nachrichten
Clara O’Brien as Carila... sang very well.. and was in addition a feast for the eyes. Badische Neueste Nachrichten
Miss Donnithorne in Miss Donnithorne’s Maggot (Peter Maxwell Davies) [more]
One of the highlights of the season for an established artist. Opernwelt
Undeniably [the director] profited from Clara O’Brien’s towering acting ability, who particularly in the mad scenes, refrained from using worn-out and over-familiar clichés. She waxed effortlessly through the enormous vocal demands of the part, the jagged vocal lines, as well as the silky lyricism. Die Welt
Above all, Clara O’Brien was fascinating as Donnithorne. The vocal versatility and musical perfection with which she profiled her part, as well as her pointed, never over-acted depiction was, in fact, an event. Opernwelt
... Clara O’Brien lent to the passion of Miss Donnithorne a rare combination of vocal quality and stage presence with great precision and conviction. [...] with much intelligence, resolve, well-controlled imagination, and active compassion. Dernieres Nouvelles D’Alsace
... sung now and again to the limit of vocal extremes and almost wildly portrayed ... brilliant ...long-celebrated... Opernwelt
... sung ... by the excellent Clara O’Brien. London Finanacial Times
... the title role was ideally cast. When Clara O’Brien yearns for the land where the lemon trees bloom, we, too, in the audience believe we sniff some of the fragrance. She is through and through a graceful creature with a dark fragility and a secretive voice whose soul is given breath by a great loving heart. Stuttgarter Zeitung
Clara O’Brien was very impressively cast in the title role... the singer showed an astounding range of vocal expression. She expertly portrayed every facet of Mignon by subtle means and, in an ideal way, mirrored the light, somewhat melancholy flavor of the music. Die Rheinpfaltz Zeitung
...with her maiden-like charm, captivating aura, her rich vocal gifts and with her lyric, soulful performance she bewitched the audience from the first moment. Badische Neueste Nachrichten
Polly Peacham in Beggar’s Opera
Clara O’Brien through her charmingly performed airs and her sassy portrayal was wonderful. Die Rheinpfaltz Zeitung
Dinah in Trouble in Tahiti
The role of Dinah was sung by Clara O’Brien who was armed with a beautiful vocal timbre and good acting skills. Her singing of, “I Was Standing In a Garden” was gorgeous and a high point of the 50-minute work. Classical Voice North Carolina
The greater part of this exemplary performance [of Mahler’s Rückertleider] came from… Clara O’Brien, through her clear and highly expressive diction in which each tone was intricately formulated. Her deeply intimate expressiveness made her shine as superb interpreter of Mahler’s music. Die Rheinpfaltz Zeitung
Hector Berlioz' song cycle “Les Nuit d’été” from Gautier are amoung the most intimate and densely atmospheric compositions of this French genius with now delicate, now melancholy, often fantastically poetic music. These elements, with their clear intimacy found in the mezzo soprano Clara O’Brien an interpreter who sang stylistically true while constantly creating a deeply effective atmosphoere. Die Rheinpfaltz Zeitung
Clara O’Brien led the soloists [of the Bach St. Matthew Passion] with a cultivated mezzo timbre as well as poignant expression. Die Badische Neueste Nachrichten
Naturalness seems to be the secret with which Clara O’Brien makes one almost forget that her efforts are not only great, but beyond that, also enormously difficult art.
[T]he mezzo-soprano belongs to the category of aspiring artists who have made it their goal not to follow the traditional interpretations of art song, but rather to find a way to bring a completely fresh, colorful and textually appropriate expression to the songs.
Her charm was present not only in the presentation, but also in her apparent effortlessness with pitch accuracy, tone production and the extreme intervallic leaps of the overflowing melodic lines, as well as the lively feeling and musical expression. The voice appeared effortless even when springing over the borders of her voice type so that it would be difficult to decide how to categorize it. Is she is a soprano with a beautiful alto richness in the lows or a mezzo soprano with a particularly impressive upper range?
[Her] particular expressiveness in her song interpretation was especially evident in the widely differentiated diction, which is seldom successfully accomplished by singers in the genre. Her voice had a warm-tempered timbre and showed itself effective and even in all registers. An ideal condition to which Clara O’Brien added her superior song gestalt.
She controls not only a faultlessly-produced magical voice but, due to her perfect technical training, she can do with it what she wants, how she wants.
From the very first moment the listeners were touched by the beauty and evenness of her voice, as well as by her sensitive warmth. The expression at the end, demonstrating a purposely restrained sense of transcendence, yet so clearly “spoken”, was an especially beautiful example of mature Lied interpretation.
Clara O’Brien brought to the stage a perfectly polished performance...of the love lament “L’Astratto” from the early baroque composer Barbara Strozzi. O’Brien’s artistically expressive performance was stylistically above question and completely satisfied the composer’s wishes.