To back them up in Smith's time as well as today. It was not a bad idea and a very good gimmick as well for Smith as he had the talent and ambition to do both.
However with all dancers, aging can kill your dance popularity, but not the music/song... So as he aged it became more "back to song" than dance for him.
On some of his sheet music or dance flyers you can see he performed the dance as well s wrote the songs for it. He was not the first, the only, or the last person to do this, but his music was more popular than most of those who did it at the time but would be remembered for his music more than his dances over time and the dance side would be probably forgot about as well if he didn't have a few high profile females partners.
It has been written that it was he and Francis Demerest who introduced the Tango to the United States, danced the Apache dance with Louise Alexander as well as promoting new dances of the time. Since a new era was emerging in dance forms, Smith would become a musical pioneer as well as a dancer ( Similar to Perry Bradford) helping to displace the marching bands with 'dance bands' by creating his own dance Orchestra ( Joseph C. Smith Orchestra and also known as The Joseph C. Smith Trio and finally the Joseph C. Smith and His Mount Royal Hotel Orchestra).
Smith's Orchestra began recording for the Victor Talking Machine Company on September 25, 1916 and Brunswick around 1923. Mr. Smith had been an important factor in Metropolitan dancing circles. Smith paved the way for Paul Whiteman and Isham Jones Orchestra's, and others of the 1920's. Joseph C. Smith's music was to became out of fashion though by February 1922 but he is remembered as his arrangements show his attempts to jazz up the banal dance tunes of his time.
The 1915 movie entitled 'the Apaches of Paris' portray him dancing the infamous Apache dance with Laura Hamilton. Smith lost his savings in the Wall Street crash of 1929 and spent his last years in Florida. Around 1923 he moved to Montreal, Canada and played at the Mount Royal Hotel. His last known recording is dated 1925 under the name "Joseph C. Smith and His Mount Royal Orchestra". Moved from New York to Miami Florida in 1945 and called it home. Joseph C. Smith, 81, of 1048 Alton Rd., Miami Beach died at his home on Monday 3/22/1965. His wife was his only survivor.