Popera

IL Divo is probably the most well known popera band

Popera, as its name suggests, is Pop + Opera - it is pop music performed in an operatic style or classical music styled as pop. According to Wikipedia, the word popera was first coined by Scott Paul-Young, a British theatre agent, to best describe the music that was being created by producer Malcolm Middleton and performed by the opera girl band Milan for the first time at The Hippodrome, London in August, 2001. Middleton created the idea of an opera band mixing traditional opera with contemporary pop and dance music earlier in 2000.

However, some critics consider popera as 'commercialized operatic music'.
A critical article, by Oliver Kamn, debating the genre on The Times (UK) says:

The managing director of EMI Classics UK justifies popera, and its close relation “crossover”, as “trying to get great melody to as large an audience as possible”. But melody is not music. It is one of the vehicles of music. The Western musical tradition is about the development of shifting relations between melody, harmony and musical form.

Popular music, by contrast, is almost entirely about repeated melody, without musical development. It depends for its potency on an immediate sensory impact on the listener. Classical music that does the same thing is no longer classical music. Opera with the excision of the drama of which the aria is an integral part is doubly diminished. Getting popera to as large an audience as possible is an aim of startlingly attenuated ambition. Being, in all essentials, pop music, it has already got there. [...]

If popera has any rationale, it is that this is a false and stuffy distinction, and that classical music needs to be stripped of its forbidding complexity to be more widely appreciated.

And finally, a little fun fact: the official song of the 2006 FIFA World Cup is a poperatic song.