Both pieces date from the glorious, late phase of Janacek's career when virtually everything he composed was an expression of his infatuation with a girl 38 years his junior. They are confessional quartets; music that had to be written and that couldn't possibly have been otherwise. The First Quartet is the shorter of the two, a hot-blooded, unpredictable essay, where sudden dramatic interjections and restless rhythmic patterns are leavened by passages of great lyrical beauty.
It's a sort of stream of consciousness that somehow establishes its own form. Janacek's specific inspiration was the novel, Kreutzer Sonata, by Leo Tolstoy, and the seething tensions of marital jealousy that fill the book are granted a musical soundtrack to match.
The playing of the Guarneri Quartet combines heightened sensibilities with a pooled interpretative wisdom that is only possible when a group has been playing together for many years. But don't expect easy listening. There are plenty of rugged accents, and the spur of the moment is never dulled, though in the Second Quartet - the one sub-titled "Intimate Letters" which Janacek dedicated specifically to his youthful beloved - the Guarneri Quartet softens the mix with a mellow, reflective quality that pays highest dividends in the outer sections of the gently rocking third movement.
Speed changes are common throughout both works but, again, the Guarneri Quartet is adept at balancing heart and head: everything is superbly controlled, no detail left to chance and phrasal articulation is pin-sharp. The recordings are superb.