"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.
Capital FM Jingle Bell Ball Dec 6, 2015 London, England, United Kingdom Uploaded by Belieber Dianaa
EDC Las Vegas 2015 Jun 19 - 21, 2015 Las Vegas, Nevada, United States Uploaded by Kiana Uyeda
