Each time I do an arrangement for Play It With Moxie, or any other group, I go through the same few steps before I ever start writing notes.
When you decide to cover a song, your first decision is whether to make a faithful reproduction or make it your own. Reproducing the recording has several benefits. The audience will respond to the familiar. With a transcription you can hand out the sheet music, play the recording, play along with the recording as a group, play it without the recording, and have the song ready very quickly.
On the other hand, if you learn the original improv solo you will be assured of capturing the style but not necessarily the soul; and you might be as good as the original, but you will not be better. Personally, I’d rather have my bandmates’ minds in the moment rather than trying to pull from some distant recording. If you create your own version, everyone’s had a chance to put their stamp on it, to get invested, to be eager to share with the audience. Also, if you do it straight off the recording, the audience may not care because they could just listen to the recording. You will never sound as much like the original band as the original band does–you may be better, but you won’t be more like them than they are.
You may not have a choice. If your band doesn’t have the same instruments or voices, you might not be able to pull it off. I prefer to take it consciously in a different direction, put a different beat to it, play it like you play some other song–especially if not all the players are familiar with the recording. Sometimes it’s best to hand out lead sheets at a rehearsal, have someone play it solo, then have people join in and make an arrangement out of a jam. Still, you’ll have to preserve the characteristic recognizable parts somehow, if only in the introduction or chorus.
Finally, you don’t have to use everyone all the time. There’s a lot to be said for playing your strengths and not getting in your own way. Bottom line, you need to know your players, their instruments, their capabilities, and how they blend. That’s going to come from trial and error, and that’s a worthy way to spend rehearsal time.