Which major outdroo entertanmenteventinromewasaccompanied?

It seems like your question is incomplete or contains some typographical errors. If you're referring to a major outdoor entertainment event in Rome, you might be thinking of events like the Rome Film Festival or the outdoor concerts held at venues like the Circus Maximus. These events often feature a mix of film screenings, live music, and cultural showcases. Please provide more details for a more specific answer!