Canada's Duo Concertante is a young married couple, and you might think that tackling the numerous interpretive challenges of Beethoven's sonatas for violin and piano would strain the best of marriages. These works are a mixed bag consisting mostly of youthful pieces in transition between the earlier, piano-dominated conception of the genre and the more equal relationship between the two instruments that prevailed from Beethoven onward. Beethoven's set of ten is capped by two undoubted masterpieces: the ferocious Violin Sonata No. 9 in A major, Op. 47 ("Kreuzter"), a work that bespeaks as well as any the political tumult of the age and adds an intriguing ethnic dimension (Beethoven toyed with the subtitle "Sonata mulattica composta per il mulatto Brischdauer [the Barbadian-Polish violinist George Bridgetower], gran pazzo e compositore mulattico" (Mulatto Sonata composed for the mulatto Bridgetower, the big, crazy, mulatto composer), and the luminous Violin Sonata No. 10 in G major, Op. 96. In the latter piece, which anticipates the economy and the transcendental quality of Beethoven's late masterpieces, the Duo Concertante is at its best. The performances, played on modern instruments, are straightforward, quiet, and generally not far from the middle of the road, and their distinctive quality is the close sense of ensemble that may sometimes develop among family groups or other duos of long standing. The Op. 96 sonata unrolls here with an arresting lightness and grace. The earlier sonatas in general contain nothing that will change one's understanding of the music, but they again benefit from an organic-seeming quality deriving from the relationship between the performers and aiding the problems of balance in these works. The "Kreutzer" sonata's big first movement is taken quite slowly, and the performance never quite catches the weight of this work. As a whole, this is a reasonable budget choice of Beethoven's violin sonatas, with the best saved for last.