merging different voices

[Federico Camara Halac]

Hello list, 

This is my first post here and I’m fairly new to Lilypond, but I need some 
help. I am using Lilypond to compose, and I need to merge 4 scores into one. 
All four scores have the same 6 instruments and time signature (4/4), and all 
rhythms fall into the same grid of 16th notes. 

What I imagine by ‘merging’ is something like superimposing pixels (multiply, 
add, substract, divide) but applying this to the 16th-note ‘pixel’.

Is this something that can be done within Lilypond? Any suggestion would be 
really appreciated!

Thanks!

Fede