On July 11, 2016, vocalist, guitarist and founding member Paulo Miklos announced he would leave the band to focus on his personal projects. He was then replaced by session member Beto Lee, son of Brazilian notorious rock singer Rita Lee.  His first recording with the band is a version of "Pro Dia Nascer Feliz", originally by Barao Vermelho, for the soundtrack of the 24th season of Malhacao, a Rede Globo series. With Lee's inclusion, the band recovered some old songs for its live setlists, including Titanomaquia's "Sera Que E Disso Que Eu Necessito?" and " Nem Sempre se Pode Ser Deus". They also started to have Bellotto sing in some songs.  Also in 2016, the band announced a new album for a possible 2017 release. According to Bellotto, it will be a rock opera, and the band intended to enter the studio until mid-2017 so the album could be released in the year's second half. Drawing inspiration from albums such as The Who's Quadrophenia and Green Day's American Idiot, the over 30-track rock opera will have its story written by Hugo Possolo and Marcelo Rubens Paiva. By April 2017, Mello said a handful of tracks were ready.  Also in April, the band started a tour called "Uma Noite no Teatro" (A Night at the Theater) with a show that was also the inaugurating event of Shopping Villa-Lobos' theater Opus. The tour included three new songs: "Me Estuprem" (Rape Me), about sexual harassment and rape; "12 Flores Amarelas" (12 Yellow Flowers); and "A Festa" (The Party). By that time, none of them were expected to be featured in the band's next album. On 23 September, however, the band performed them again during their show at the Rock in Rio 7, and this time they were announced as part of the new project. On December 2017, they announced that they had already started recording the album and that it would be released via Universal Music. In January 31, they announced that the opera rock would be released in early 2018 and that its title would be 12 Flores Amarelas.

Answer this question "What was the rock opera?" by extracting the answer from the text above.
a new album for a possible 2017 release. According to Bellotto, it will be a rock opera,