In it's consistent equality of the two instruments and the unprecedented, almost symphonic sounding content severity represent the Sonatas Op. 5 a quantum leap in the evolution of classical chamber music for solo strings and piano is. This seems all the more at amazing than Beethoven got on here with no direct precedents and to the so-called "Kreutzer Sonata" Op. 47 from 1802 in this field and nothing like it has created. In addition to the two sonatas Op.5 Rainer Zipperling and the Bulgarian fortepiano specialist Boyan Vodenitcharov two in close temporal proximity resulting variation cycles Wo 45 and Op. 66 added on Themes by Handel and Mozart, which are characterized also by effect full of music cello and piano