Scottish music varies from district to district. The style & tempo differ completely from say Shetland, to the western islands. Shetland music is faster, and favours a strong Scandinavian influence, Music in the west is slower and favours more Scottish gaelic tunes.
You'll find Scottish songs differ from area to area too as do Irish ones.

Do a google for favourite Scottish songs and also tunes and listen on you tube
Then do the same for Irish