Opira Christopher Callo famously known  by his stage name as "Big G Star" is a EastAfrican (Uganda) Hip-hop Artist who raps in English and Luo(Acholi).

He  was born in the mid-90s in Kitgum district. Big G Star went to various schools like Midland High school,City High school,St Lawrence London College and later he finished his A level from Kololo Senior secondary school.He graduated from Kampala International University.

Big G Star started his music carrier  when he was still in High School but later at the University he began doing serious music like Aminah and Excuse My Runyooroo which was voted as song of the year in 2018 Banyakitara Music Award in Bunyooro later on "Big G Star"  Released Monster hit that took over Air waves in Northern Part of Uganda dubbed "KOPANGO" which means "How Are You" he later did a song called "Kaya Wek Akayi" meaning 'Bite me I bite you' Currently Big G Star is  working on alot of Songs in Studio and he argue his funs to follow him on  his social media platforms  for any new project.