The term 'Waltz' refers both to a traditional Austrian dance in triple time, and to the musical form which accompanies it. The waltz is almost always written in a 3/4 signature, using a harmonic rhythm of a chord per measure, with the root of the chord being played in the first beat and the remaining notes as a block on the second and third. Though notable composers had written waltzes as early as the late 18th century, they were mostly intended as dance accompaniment. The adoption of the waltz as an artistic form intended for listening only is probably marked by Chopin's sets of waltzes for piano solo. Since then, a great number of important composers have written waltzes, even outside the German sphere (for example, Maurice Ravel's 'Valses nobles et sentimentales'). Waltzes are usually considered light music, not suitable for heavily dramatic purposes.