Well, first of all I would be pretty firm with the rest of the cats about solo order. You know, guitar gets first solo, then piano, then me, then let's trade 4s - or something like that. My main issue is that it doesn't sound like anyone is listening to each other, everybody's kind of in their own little world. I know everybody's a beginner and we all have to start somewhere, but playing together is the goal. Like Jim Hall said, when someone asked him to define the swing feel, he answered "Camaraderie!"
One of the things that I really worked on with Joe was trying to play lines that were ONLY quarter notes, center of the beat, no anticipations, slides, ghost notes, triplets, etc. JUST quarter notes. If you can get together with your drummer before the session (or hang afterward), play through a couple of tunes - you walk JUST quarters and s/he plays JUST quarter notes on the ride cymbal. Try to get so that the attack of your note and the attack of the bead of the drumstick on the ride are indistinguishable. That you are making the cymbal sound and s/he is making the bass sound. And then anytime that you are playing with the group and it feels like things are not jelling time wise or feel wise - get back to that synced in feeling of the ride and the bass note. Let note choice go, if you have to, in order to make the rhythm solid.
I do have to disagree with a few things Mushroo said.
1. "...you can throw some of their same musical ideas back at them. In jazz circles, this proves you are a good listener and shows respect!" Just. Say. No. Nothing interrupts a conversation faster than someone repeating back something you just said, just as you are saying it. It's NOT supportive, it's NOT interactive. And, to me, it's a sure sign of amateurism, not experience.
2. "...more "jazz style" phrasing. Longer, legato phrases of swinging 8th notes." You want to PLAY, not SOUND LIKE you can play. All you need to concern yourself with is shutting out that little voice on your shoulder telling you what you should play, and judging what you are playing, and just strive to hear the arc of notes that are your response to your aural environment. Particularly when you solo; Joe's advice to me was to NOT PLAY ANYTHING until you just couldn't stand to NOT BE PLAYINg, and then the next thing to come out of your instrument will be closer to what you are really hearing in the moment. It is something that is hard and most lesser experienced musicians have a hard time just taking their hand off the instrument. They have to PLAY ALL THE TIME or something terrible will happen and the music will stop (which is one of the reasons the piano player jumped in when you left a breath in a phrase at the beginning of your solo when you quoted the melody) so there is this constant barrage of notes to fill any and every space. But it's mostly gibberish, and you DON'T want to speak gibberish. Everybody in the band needs to understand that rests are notes, too. And that melody, accompaniment, and solo incorporate RESTS AS NOTES in order to provide structure and form to the music.
Can you give me a little idea as to what these session are? Friends getting together, cold call sessions with different folks showing up at different times, structured workshop type sessions with personnel who don't really know each other outside the "class"? One of the great things about the group of folks I played sessions with there was that any of us could wave something off in the middle of the tune, off something wasn't happening - someone wasn't hearing a change, if the time got funny, if they needed to work something out, etc. SO it wasn't just start the tune and hope for the best, everyone was more interested in getting some music going , not just getting through a tune. That's easy to do without a lot of discussion if everyone knows (and actually likes) each other. It may be harder in a more "formal" setting, but I have found that, if you ask with the explanation that it's for you to try to work some things out and make a better personal contribution to the music, most folks are amenable. I'm not saying do it in every tune, but I think if it happens with at least one tune every session, that "permission" will be asked by other members of the group AND the ensemble playing will improve...