"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.
Reading Festival 2016 Aug 26 - 28, 2016 Reading, England, United Kingdom Uploaded by Roobyna
BBC Radio 1's Big Weekend 2016 May 28 - 29, 2016 Exeter, England, United Kingdom Uploaded by Charlie Spadone
