"Sigma" can refer to;
These are photos from concerts where Sigma played, so they may be of other bands that played the concert as well.
SW4 2019 - Saturday Aug 24, 2019 London, England, United Kingdom Uploaded by Patrick Stone
Pukkelpop 2019 Aug 15 - 18, 2019 Kiewit-Hasselt, Flanders, Belgium Uploaded by Gittelenaerts
Pukkelpop 2019 Aug 15 - 18, 2019 Kiewit-Hasselt, Flanders, Belgium Uploaded by Marloesvg
