Well, music just will not stay in family lines, it wanders from house to house... not like a nice respectable tartan!

Only useful hint I can offer is get a detailed map of where the folks came from, write town town names, Loch names, rivers, etc. and start punching them in the DT one at a time, see if anything hits...

Also, there is a wonderful book (one of O'Neill's?) which relates little bios of the great Irish pipers and other musicians. So, does anybody know of a similar work which might be mined for Scottish musicians of the Ross persuasion? You might find they wrote some stuff which survived.