Scale tool and chords

Hi everyone

i am just programming a little tool in max for live which is sending chords to sequencers, so you can play chord progressions with many sequencers at the same time.

i also now want to ad some scales there for bass or lead sequences, i am doing research since a while, but still i am a bit lost.

first scales i would probably use are the pentatonic scales.
i could play for every chord the corresponding pentatonic scale, doesnt matter in which key the whole song is right?

So whatever the song is in C-, G- or F-Maj all notes of the Major-pentatonic scale in c are good on top of the cmaj chord and its tensions??? right?
same goes for the minor pentatonic and the minor chords?

But with other scales i cant do this, because there will be lots of tones which are not in the key of the song right?
The problem is people will set a sequence, like play step 1 3 5 6 of the scale, one is allways the bass tone of the chord which is playing.
Now if i change the chord it will play 1 3 5 6 of the scale which corresponds with the new chord.

There is also the option to use the scale of the key, so when the song is in c maj just use this scale and change the modes of the scale corresponding to the chords, som play dorian with d-minor and so on.

i would like to understand a bit better the relationship between chords, the key and the scales.
in the scale tool you can choose chords and not the key, so i thought there might be an option to play a scale to a specific chord and it will always fit into the key of the song...

arghh... long confusing post
hope someone will get what i mean :)

with the chords i did it like this, every sequence can have six notes which correspond with the six strings of the guitar.
The six notes are C-2, C#-2, D-2 and so on. N
ow i just transpose the six notes to the notes of the chord which the user i choosing, i was adding the chords from the tabs on this page, each chord can have three inversions as well.

But still it will keep on playing the same sequence, like 1 2 4 3 6 5, (which are the strings of my virtual guitar)

Now doing the same thing with scales is giving me some headache...
maybe someone has an idea???

Robert