I sang it at Gaudeamus singing party in 2018, now finally got to know what is it all about :) It sounds just like 'Seitse meest pandi sadamas pokri' in major.
I don't think it was by Ugniavijas, This song was first sung in 1931 Heres the link ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-EfEAk8vCPis.html The original version