A Viennese waltz (Valse in French, Walzer in German) is a music and dance which started in Vienna in the late 18th century. It is a ballroom dance in 3/4 time. It is the most famous of all dance forms. It became extremely popular during the 19th century, and is still danced today. Many famous composers wrote waltzes for piano or for orchestra. The rhythm of the waltz can be heard in lots of music, not just in pieces which are called a 'waltz'.