A Maneskin concert does not need an apostrophe. Maneskin is functioning as an adjective describing the noun concert. The Eurovision Song Contest also has no apostrophe. This is the full name of the contest. Saying they were formed by the contest sounds strange. Do you mean they were formed for the contest? The band was created in order to compete in the contest?

Sure! ✅ Maneskin concert — no apostrophe (name as adjective) ✅ Maneskin’s performance — apostrophe shows possession Use apostrophes only when showing ownership, not when the name just describes something.