But above all, up to the late 1950s Grappelli was still working on perfecting his instrumental skills. While his solo choruses on the violin with the Quintette du Hot Club de France mainly involved intensifying ornamentations, tension-escalating vibrati, glissandi and tremoli, short fill-ups and improvised melodic phrases, in the years after the end of the war he expanded the range of forms of expression on his instrument. He was inspired, for example, by the ''Bel Canto'' playing of the classical violin virtuosos, taught himself different type of bow strokes, and learned an unusual grip technique for the violin in order to be able to fly over the strings with the minimum of pressure. But above all he emotionalized his sound using a technique with which he preceded the played notes with a glissando from below. Stéphane Grappelli's visit to Studio 1 at the Norddeutscher Rundfunk in Hamburg in 1957 was then indeed a stroke of luck. Because on this day he had for the first time the complete repertoire of forms of expression on the violin which made him the style-forming jazz musician who earned the admiration even of instrumentalists in other genres such as the great classical violinist Yehudi Menuhin. At the same time, his tone and phrasing still had the vitality and virility of his younger years with the Quintette du Hot de France in the 1930s. And even more: In 1957 he was able to build a bridge with his violin between the swinging grandezza of the US jazz musicians and the great tradition of European music.