When Mamie Smith recorded "Crazy Blues" for Okeh in 1920, little did she or her Svengali-like manager Perry Bradford have any idea what effect this would have on the recording industry or popular music in general. The astonishing success of this record caused shockwaves in the normally ultra-conservative recording industry – which was still recovering from the popularity of jazz and the apparently insatiable demand for dance records. These two factors combined in the demand for slow or "blues" fox trots, fueled by the success of vocal blues records and booming sheet music sales for "blues" compositions. From the spring of 1921 instrumental blues were increasingly featured by recording groups, composed and published mainly by black songwriters but performed by and large by white bands and orchestras. The impact of the blues craze on the recording companies can be gauged by examining the output of the era's best known jazz group, the Original Dixieland Jazz Band. From their first session in 1917 to the spring of 1921 most of their output comprised of original compositions by members of the band. From the spring of 1921 to their departure from Victor at the end of the year, all of their records were instrumental blues composed by black songwriters. One by one the recording companies either hired or "created" bands for the sole purpose of recording "blues" numbers, and to add a