Reviews:

Kreis-Anzeiger (Germany) 25.2.2008
The musicians of this evening were a stroke of luck.
With the “Poco Allegro” movement of Bohuslav Martinů’s contemporary “three madrigals” for violin and viola the duo showed that string instruments are able to sing, producing delightful cantabile sounds.
Song likely and with the classiest of ease they played Giovanni Pacini’s Cavatina “Cara adorata immagine”.
Gorgeously played was the bravura piece of the duo, Paganini’s "Il Carnevale di Venezia" as well as two Piazzolla Tango’s – the early composition “El Desbande” traditional and dancing, the second “Invierno Porteño” with all the erotic tinged melancholy, as we know from this composer.
An evening that the audience enjoyed so much that it concluded with their enthusiastic applause.

"New York Concert Review", spring 2007 edition, by Anthony Aibel, about the Carnegie Hall concert:
"Halaf and Langheim, string duo, respectively from Israel and Germany, performed virtuoso material that was polished, fine-tuned, passionate and engaging. Piazzolla's Otoňo Porteňo, arranged for string duo by violist Langheim, was a piece of fine craftsmanship and showed a performance of solid preparation; Handel-Halvorsen's Passacaglia was rich and Strong-toned."

„The musical contributions of the young couple – among them works by Robert Stiegler, Joseph Haydn and W.A. Mozart – were rewarded with thundering ovations of the mainly senior audience.“

Musical interludes on high level During the musical interludes the two show the class, that the top-level-orchestras demand on them.“

Succeded blend of texts and music ... with a sophiticated, from accentuated recited verses and masterly interpreted pieces, compounded program, appeared G. Biwer (recitation) as well as Hagit Halaf (violin) and Christoph Emmanuel Langheim (viola). With perfect coordination of violin and viola Hagit Halaf and Christoph Emmanuel Langheim enchanted the guests“

Christopher Hogwood (Conductor):
Their interpretations are honest and fresh, with a fine sense of style. Besides excellent playing, great care goes into their interesting choice of repertoire.

The EpochTimes Israel:
He and She Israeli and German with viola and violin
- the music speaks for them and the audience gets emotionally involved.
when they are armed with their instruments, they succeed more than anything else to express the advantage of music as a powerful instrument for reconciliation, approach and heart uniting on one hand and on the other hand as a medium for universal messages that cross borders and nations.
these two instruments belong to the same family of sound and this is what made it possible to Hagit and (Christoph) Emmanuel to combine their companionship to musical harmony, where the violin and the viola can sound like two violins, like violin and cello, like viola and cello or like two violas whatever they choose.
He seems to be born with the viola in his hand, with sensitivity and calmness he produces gentle and delicate sounds and she gives the tone with the violin.
In their playing the two give space to the artist as well to the human being. Behind their professional identity are roots and sorrowful history that are not contradicting the universal message.