"Karen Foster [as Isolde] made an impressive debut, with a solid voice and convincing power.... She internalized the strength of Wagner's character."
-- Ragnhild Veire, Kultur-og-underholdning
"Karen Foster (Isolde) is powerful, and has a voice filled with nuance."
-- Olav Egil Aune, Vårt Land
"Karen Foster's Isolde fills the palette of emotions with conviction and flexibility, which will probably even increase in coming performances."
-- Ida Habbestad, Aftenposten
"Karen Foster as Isolde is an elegant dramatic soprano."
-- Ståle Wikshåland, Dagbladet
"Karen Foster has a powerful voice and portrayed the character well. The pinnacle was the final aria, 'Mild und leise.'"
-- K. Moe, Kultur Speilet
Ms. Foster dominated the orchestra with her powerful sound and excellent coloratura.
-- Rosamunde Hatch, The Westfield Leader
... soprano Karen Foster emerged as a standout in the role of Donna Elvira. The attractively cool and instrumental timbre of her voice is reminiscent of the young Karita Mattila, and she negotiated the tricky hurdles of "Mi tradi" with the confident assurance of a diva of tomorrow.
-- James Jorden, Gay City News
Tuesday, May 9, was a special night for opera lovers. The setting for this exciting event was at the Kosciuszko Foundation in New York City. … Karen Foster revealed a big golden Wagnerian voice in her superb singing of “Dich Teure Halle” from Wagner’s Tanhauser.
-- Nino Pantano, The Italian Voice