This is a bit of a long winded question, but I’ll try to articulate everything I’m wondering. I was listening to “Havona” by Jaco Pastorius (big band) and I want to be able to create bass solos similar to how he does it in this song. I believe the key of this song is E, but as I was watching a video of someone covering it on YouTube, he was hitting a bunch of notes that were out of the key of E. These notes gave it that jazzy sound which I want to achieve. How would I begin to practice jazz phrasing like this?: How does this guy(or Jaco) know which notes to hit that are out of key? Should I learn all the chord changes behind the song first, then pick apart the notes in the chord to phrase my solos in? Some general tips on approaching learning this type of music would be greatly appreciated. Any particular scales/modes to be proficient in? I want to learn how to do this so that I can make my own songs and phrase over the chord changes in ways that I’ve never done before. thanks!