Crossover singers are simply those who occasionally sing some material outside of their main genre, and obviously crossover singing of various kinds has been with us for a long time.
More recently, though, a group of singers including the likes of Sarah Brightman, Charlotte Church, and Andre Bocelli have turned the singing of classical material by popular singers into what has become a popular genre of its own.
It has not been all one-way traffic. Along with popular singers covering operatic and classical material, a number of trained opera singers, including Bryn Terfel, Natasha Marsh, and Vittorio Grigolo have produced crossover albums hoping to cash in on the popularity of the genre.
And, of course, the beginning of classical crossover as a truly popular form of music goes back to the famous "three tenors" (Pavorotti, Careeras, and Domingo) tours when the three top opera singers brought a mixture of operatic and popular material to huge crowds, and produced enormously successful albums.
Popera
The term "Popera" (Pop + opera) has recently become popular and is often used synonymously with "classical crossover" or "crossover".
Strictly, rather than being a synonym for classical crossover, the term applies to the singing of opera material in a popularised, but still operatic style.
The distinction is a useful one. Popular singers like Katherine Jenkins, Paul Potts, and some members of Il Divo have all had operatic training and sing many arias and other classical material using an operatic style of singing.
On the other hand singers such as the Norwegian Sissell, Nana Mouskouri, and Hayley Westenra are essentially singers of easy listening ballads, who do the occassional aria or classical piece, but who aren't operatically trained and do not affect an operatic style.
The Crossover Controversy
In fact there are two separate areas of controversy. First there is the inclusion of many singers in the UK classical charts and in competition at the Classical Brits, who the classical purists feel do not belong there; and secondly the belief many purists have that crossover somehow dilutes or harms "real" classical music.
The "Easy Listening Brigade" on the charts and at the Classical Brits
The classical record charts have been dominated for several years by singers such as Charlotte Church, Russell Watson, Katherine Jenkins, and Hayley Westenra whose albums -- according to the classical conservatives -- are not "classical" music at all. More recently singers like Sissel, and even Nana Mouskouri have been included on the classical charts.
This has seen the sales of "classical" music skyrocket, and the record companies are accused of artificially inflating classical music sales in this fashion.
For an album to be included on the classical charts in the UK, 60% of its content must be either "classical" or "traditional", without any "background synthesization".
