The Spanish tinge is an Afro-Latin rhythmic touch that spices up the more conventional 44 rhythms commonly used in jazz and pop music.
In fact, if you can't manage to put tinges of Spanish in your tunes, you will never be able to get the right seasoning, I call it, for jazz.What Morton called "Spanish" were the tresillo and habanera rhythms of the Cuban contradanza ("habanera").
Morton demonstrated the "tinge" to Alan Lomax in the 1938 Library of Congress recordings.
[4] Morton categorized his compositions in three groups: blues, stomps, and Spanish tinge, for those with habanera rhythms.
Morton also called attention to the habanera in "Saint Louis Blues" as one of the elements in the song's success.