Quick question first, which dial setting did you use for the Turrentine search? Essential, Balanced, or Adventurous? Each gives very different results. Essential keeps it tight to his core sound, Balanced mixes in unexpected finds, Adventurous goes deep.
Great question overall, and Blue Hour is a fantastic album.
Right now Sonic Oracle is artist-based, so when you enter Stanley Turrentine, you get artists similar to his overall catalog rather than a specific slice of his sound like the blues-influenced jazz side.
What you're describing, the ability to search by a sub-genre or style itself ("blues-flavored traditional jazz") rather than a specific artist, is something I'm actively working on. The idea is exactly what you laid out: let the engine explore a style across multiple artists who may only occasionally play in that space, rather than being defined by it.
In the meantime, try the Essential setting if you haven't already, and use click-to-discover on the results to chain deeper into that blues-jazz space.
Appreciate the detailed feedback, it helps shape what gets built next.