Thanks for the answer. Makes sense.

What I'm reading that you want to do are (at least in part)
1. improved keyboard voices
2. improved bass line
3. better compositions and better melody

Some pointers...

1. I'm not a keyboard person, so can't help there.

2. As for bass, about all I can say is that bass is a base. Like drums, it provides rhythmic propulsion... it moves things forward and provides a base to build on. Sometimes its kind of melodic, sometimes not... depends on the song or player. Best tool here is ears. Listen to the music but concentrate on the bass and visualize what the player is doing... isolate that in your listening and hear how the bassist integrates into the whole. Hear how it works and try it yourself. Are you moving things along, providing a base? Are you playing rhythmically or melodically and why?

3. As for composition/melody, I'm not a songwriter or composer but I do an awful lot of improvisation and have for a very long time. I've studied it and work on it constantly. Improvisation is a form of melody composition... you know: they are playing the changes, so now you play something new and different... invent a melody right now right away.

Some pointers maybe you can use...

- have a plan... know where you are starting, where you are going and what to do when you get there

- your melody can be chord based or scale based, leads in different directions sometimes

- your melody should have a tonal focal point... a starting and ending spot, a complete circle, a "home base"... kind of like the note everything else is wrapped around or ... its kind of tough to verbally describe, so I'm probably sounding crazy here. Just think "where's home base and how do I leave and how do I get back?"

- you can repeat phrases as long as you have some slight changes to them (otherwise they are boring)

- use a step-wise motion with few giant leaps; leap for effect now and again sure, but don't make a habit of it. Listeners often have trouble following giant leaps, it can be jarring. When you use them, use them in logical places.

- have a tonal motif.. long and short phrases, long and short notes.. it need not be complex to work

- work with the rhythm and changes not against them. In fact, start with the rhythm. If I can't "feel" the rhythm... the beat.., my improvisations frankly stink the place up.

- hum or sing it before you play it. If you can sing it you can play it.

- use repetition and contrast but not too much or because repetition can be predictable and boring and contrast can be confusing to a listener. Its like seasoning the food... gotta know when to use it and how much to use.

- know that the chorus is the song's hook, the most memorable part of any typical song. If you quote anything from any song, quote the chorus. When writing sometimes its best to start with the chorus.

Song structure is typically something like AABA where A is the "verse" and B is the "bridge" or "chorus".
Isolate the A part and the B part in your listening. Notice how the B part is different.. I mean "how" as in melody, harmony, tempo and rhythm wise how it is different structurally. Does it flow easily from the verse or is it more of a contrast? How does the A part get to the B part and how does the B part get back to the A part? (Reading music can help here... you can actually see it written out)

Lyrics tell a story but they also cement a melody in a person's brain. If I say "I read the news today... Oh, boy" or "She'll be comin' round the mountain when she comes" what do you hear in your head? Use a melody that makes the lyrics seem a natural extension of it or lyrics the natural extension of the melody. Again, hum it. Does it go up and down a lot in pitch or does one note seem to flow naturally into another? Which do you like better? Which sounds more natural?