The Arditti Quartet is a string quartet founded in 1974 and led by the British violinist Irvine Arditti. The quartet is a globally recognized promoter of contemporary classical music and has a reputation for having a very wide repertoire. They first became known taking into their repertoire technically challenging pieces. Over the years, there have been personnel changes but Irvine Arditti is still at the helm, leading the group. The repertoire of the group is mostly music from the last 50 years with a strong emphasis on living composers. Their aim from the beginning has been to collaborate with composers during the rehearsal process. However, unlike some other groups, it is loyal to music of a classical vein and avoids cross-genre music. The Quartet has performed in major concert halls and cultural festivals all over the world and has the longest discography of any group of its type. In 1999, it won the Ernst von Siemens Music Prize for lifetime achievement, being the first and only group to date to receive this award.