Richard & Danny Thompson: Sweetheart on the Barricade

What is the greatest album made by two unrelated people with the same surname?

A strong candidate must be Industry, made in 1997 by the two British legends Richard and Danny Thompson. Sweetheart On The Barricade is a track from it

As Allmusic says:

The Thompsons, joined by members of Danny's band Whatever, as well as his uncles Albert and Harry Thompson on trombones and Richard's longtime associates Dave Mattacks on drums and Christine Collister on backing vocals, incorporate jazz, rock & roll, and traditional British folk music to convey their impressions of industry through the years.

Think of it as a musical anticipation of the London 2012 opening ceremony.