Definitely Oasis

I'm sorry, but I don't have reliable information about an organization named 'Definitely Oasis' in the context of artistic venues or ensembles. The name may possibly relate to a tribute act or cover band inspired by the British rock band Oasis, known for their influence in the Britpop movement of the 1990s. Tribute bands often perform in various venues replicating the original band's music and style, but without further specific information about the location or the nature of the organization, I cannot provide more details.