Crossover music can not only provide unexpected exposure to an artist or record label, but it can expose the public to a style of music they may not be that familiar with. While some artists have been criticized by their die-hard fans for their crossover albums and songs, others have been able to find new life when they have produced an album in a new genre or style of music than they normally do.
Crossover music is when a song or album from one style of music--bluegrass, for instance--finds popularity in another genre of music sales, such as the pop music charts. This can happen when an artist who normally records in one genre "crosses over" to record in a different genre, or when a song in one style suddenly appeals to listeners of another style.
Within the realm of classical music, the term crossover is usually applied to an artist who records an album of "show tunes" or "popular songs" where they would normally only record traditional, classical pieces.
In Christian music, the term crossover is used to describe an artist who begins as a strictly Christian artist, but then finds success in the mainstream pop charts with songs that may or may not be in the Christian music genre.
Crossover country artists--such as Dolly Parton, Kenny Rogers and Glenn Campbell--are described as such because they often had hit songs that were on the country and pop music charts simultaneously.
When two or more genres cross over--not just the artist--it is often called "fusion" music because the two genres have been fused together to produce a new musical style.
Many crossover albums are unintended as such. For instance, when a classical piece is used on a movie soundtrack, it sometimes finds success on the pop music charts because of the popularity of the movie itself.