OH YOU’RE カイル! omg i think i’ve had conversations w/ different accs of yours w/o making the connection 
i know i’m just repeating myself on each reply, but plz imagine me nodding intently & scribbling notes in my “one day i’ll understand japanese” mental notebook
Hit me up whenever 
am always open with fellow weebie weebs haha 
I think the Japanese term taiban originates from the Western concept of ‘battle of the bands’, ie. multiple artists perform and the audience decides who was best. However, in VK the majority of what we call taiban shows are really just ‘shusai’ or sponsored/promotional events where either a specific label or band fronts the cost to host several artists. It’s less competitive and more collaborative, a way to help artists get to know each other and grow their fanbase together.
The literal term and origin seems it comes from that but the living language is not really saying “taiban event” event already assumes that 
That’s exactly how I understand it as well.
If you’re aiming for clarity in English, say “we’re HOSTING a concert/gig with ______” (if you’re taiban sponsor) or “we’re PLAYING a concert/gig with ________” (if you’re just one of the bands performing). Most people in English-speaking countries know that multiple bands play at one event. A one-man concert would actually be unusual. The non-hosting bands are technically considered the opening acts but still pull crowds of their own.
Don’t use event, it could imply a non-musical event like an autograph session or something to English listeners.