Rossini Stabat Mater and Verdi Requiem can be harder to guess. You can listen to them before you play. Rossini is more classical, bravura, crescendo and dense. Verdi is expressive, late romantic, popular and lyrical. (Rossini, Verdi)

Comparing baroque, romantic and post-romantic composers here. Rossini sounds classical, bravura, crescendo and dense. Puccini is very emotionally tender and realistic. Monteverdi is surprisingly realistic and expressive for baroque, but baroque instruments will usually help you decide. Be aware that Rossini Stabat Mater sounds more serious. (Monteverdi, Puccini, Rossini)

This must be a simplest comparison of most known romantic and post-romantic opera composers. Rossini sounds very classical, bravura, crescendo and dense. Puccini is very emotionally tender and realistic. (Puccini, Rossini)