...the feeling of being in love, forever"  

Originating hundreds of years ago in Bavarian Europe, the original waltz had a much faster tempo and was more similar to our modern 'Viennese Waltz'. Originally the dance experienced significant opposition when it was popularized across Europe. The idea of a man holding a woman hip to hip and cavorting about seemed somehow improper. This modern 'Slow Waltz' is  derived from an American version of the Waltz called 'The Boston'  popular in the mid nineteenth century which was characterized by the  slow tempo, long flowing steps, and the closed position which made our  slow waltz what it is today. What distinguishes Waltz as Waltz is the  character, which has been described as 'being in love- forever'.      

Waltz music is written primarily in 3/4 time, and in competitions is played at a tempo of 30 measures per minute, but tempos from 29-34 are common socially. The accented (strongest & loudest) beat is the one beat  with the two and three beats are of lower but roughly equal emphasis.