[MEI-L] Parts, staves, layer

[David Rizo]

Dear MEI List,

I have a doubt on how I have to extract parts from single score MEI files.

MEI has staff groups, staves, and inside staff layers.

From the guidelines and the samples in GIT, I’ve seen that:
- a piano is encoded in a staff group with two staves.
- the strings in an orchestral work are encoded inside one staff group
- the soprano, alto, tenor and bass in a choir may be encoded either in one staff group, in four different unconnected staves, or in two staves with two layers that belong (or not) to the same staff group.
- and many other combinations….

The perfResList element contains the different instruments, but I cannot find a common way of extracting the part played by an instrument for all these situations.

If not, do you think it would be useful to be able to connect someway the perfRes element to the layer(s) that contains the instrument part?

Thank you, 
David