I saw Nazareth more than any other British rock band, mostly because they were opening for another band. Saw them headline a couple of times and then also saw them with Deep Purple on a tour, and Aerosmith, and with Bad Company.
In the late 80s I did an interview with Nazareth for Jam Magazine in Dallas at (what was supposed to be) their very last concert ever. During that interview that I realized the movie Spinal Tap was loosely based on them.

This was their best song
https://www.youtube.com/watch?v=Rrvjm7cBWCA .