"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.
Leeds Festival 2022 Aug 25 - 28, 2022 Wetherby, England, United Kingdom Uploaded by Ellieglc
Isle of Wight Festival 2021 Sep 16 - 19, 2021 Newport, England, United Kingdom Uploaded by Mark Hags
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 Marloesvg
Pukkelpop 2019 Aug 15 - 18, 2019 Kiewit-Hasselt, Flanders, Belgium Uploaded by Gittelenaerts
SW4 Festival 2018 Aug 25 - 26, 2018 London, England, United Kingdom Uploaded by Patrick Stone
Rita Ora / MNEK / Sigma Jul 28, 2018 Dundee, Scotland, United Kingdom Uploaded by Millie Armstrong
Louisa Johnson / Charlie XCX / Sigma / Clean Bandit / Busted Jul 28, 2017 Plymouth, England, United Kingdom Uploaded by Zanevxz
Reading Festival 2016 Aug 26 - 28, 2016 Reading, England, United Kingdom Uploaded by Roobyna
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