Crossover is a term applied to musical works or performers appearing on two or more of the record charts which track differing musical tastes, or genres. If the second chart is a pop chart, such as a "Hot 100" list, the work is not a crossover since the pop charts only track popularity and do not constitute a separate genre.
In some contexts the term "crossover" can have negative connotations, implying the watering-down of a music's distinctive qualities to accommodate to mass tastes. For example, in the early years of rock and roll, many songs originally recorded by African-American musicians were re-recorded by white artists (such as Pat Boone) in a more toned-down style (often with changed lyrics) that lacked the hard edge of the original versions. These covers were popular with a much broader audience.
In practice crossover frequently results from the appearance of the music in question in a film soundtrack. For instance, Sacred Harp music experienced a spurt of crossover popularity as a result of its appearance in the 2003 film Cold Mountain, and bluegrass music experienced a revival due to the reception of 2000's O Brother, Where Art Thou?. Even atonal music, which tends to be less popular among classical enthusiasts, has a kind of crossover niche, since it is widely used in film and television scores "to depict an approaching menace," as noted by Charles Rosen
The largest figure to date for a crossover hit in the US has come from Grammy Award-winning country singer LeAnn Rimes, whose song "How Do I Live" sold over 3 million copies and spent a world record breaking 69 weeks on the Hot 100 chart, more than any other song in history, despite peaking only at number 2. It was also a massive hit in Europe.
Particular works of classical music sometimes become popular among individuals who mostly listen to popular music. Some classical works that achieved crossover status in the twentieth century include the Canon in D by Johann Pachelbel, the Symphony No. 3 by Henryk Górecki, and the second movement of Mozart's Piano Concerto No. 21, K. 467 (from its appearance in the 1967 film Elvira Madigan).
Within the classical recording industry the term "crossover" is applied particularly to classical artists' recordings of popular repertoire such as Broadway show tunes, or collaborations between classical and popular performers such as Sting and Edin Karamazov's album Songs from the Labyrinth. Early examples of this are Deep Purple's Concerto for Group and Orchestra (1969) and Gemini Suite Live (1970) as well as Rick Wakeman's Journey to the Centre of the Earth (1974) and The Myths and Legends of King Arthur and the Knights of the Round Table (1975). Metallica's S&M (1999) and Timeless Melodies (album) (2008) by Tally Koren (musician) is the most recent example of Classical music Crossover.
Vocally, the most popular crossover artist was American tenor and film star Mario Lanza, although there was no such recognized genre as "crossover" at the time of Lanza's greatest popularity in the 1950s. Signed to RCA Victor as an artist on its premium Red Seal label, Lanza's magnificent voice reached beyond classical music-buying audiences. His recording of Be My Love, from his second film, The Toast of New Orleans, hit Number One on the Billboard pop singles chart in February 1951 and sold more than 2-million copies, a feat no classical artist before or since has achieved. Lanza recorded two other million-selling singles that made Billboard's top ten, The Loveliest Night of the Year and Because You're Mine. Five of Lanza's albums hit Number One on Billboard's pop album chart between 1951 and 1955. The Great Caruso was the first and to date is the only recording comprised exclusively of operatic arias to reach Number One on the pop album charts. The Student Prince, released in 1954, was Number One for 42 weeks. No classical label artist, including The Three Tenors has achieved the success on the popular charts that Mario Lanza did in the 1950s with the exeption perhaps of Andrea Bocelli.
Dream Theater had a very strange and unexpected crossover with their song "Pull Me Under" in the early 1990s. Their style of progressive metal was never intended for mainstream audiences, and yet the song received extensive MTV rotation and radio play.
During the late 1960s, Glen Campbell began aiming his music at the mainstream pop charts, adding strings, horns and other pop music flurishes to such songs as "Witchita Lineman", "By the Time I Get to Phoenix", and "Galveston", which allowed his music to chart both in country and pop. While such artists as Lynn Anderson and Charlie Rich followed Campbell's example into the early 1970s, it was Dolly Parton and Kenny Rogers who, during the mid- to late-'70s came to personify the concept of country pop crossover, with both artists maintaining a consistent presence on both the pop and country charts well into the mid-1980s.
The term "crossover artist" may refer to musical performers and groups that are Christian music artists, who many times originally are marketed through Christian record labels, radio stations, churches and other Christian media but who start selling in mainstream secular markets as well. Other times, crossover artists may start out in the mainstream market but have Christian undertones or themes if not overtly Christian. The term "crossing over" is used to describe when an artist who had started predominantly in Christian markets starts receiving mainstream success. Some people may feel that the artist is betraying the church for fame or glory, while others may see this as a great opportunity for the artist spread the message of their Christian beliefs.
The first major artist crossover was by Amy Grant, with her 1985 album Unguarded and 1991 hit song "Baby Baby" from the highest selling Christian album Heart in Motion. The albums and single were distributed by a Christian label but received heavy play on pop radio stations and was a chart-topper on the Billboard charts. Since then, many artists have been labeled as "crossover artist" regardless of whether they originally intended to market to the Christian market, secular market, or both. The most notable recent Christian crossover artists are Kirk Franklin, Switchfoot, Lifehouse, The Afters, Relient K, and many of the artists on Tooth & Nail Records such as MxPx, Underoath, Emery, Lifehouse, and Dead Poetic.
Besides describing music of a distinct genre that becomes broadly popular, the term "crossover" has sometimes been used to describe music that deliberately mixes genres, whether or not this music proves to be popular with a mass audience. "Fusion" is a more common term for this phenomenon. Examples include jazz fusion, Celtic fusion and worldbeat. An example of crossover of jazz and classical music is the Danish 7-piece chamber orchestra "Mad Cows Sing", which fuses composed and improvised music. Other examples of crossover in music are bands that play a mix of genres such as funk, rap, rock, metal and/or punk, for instance bands like Faith No More, Red Hot Chili Peppers, Primus and Rage Against the Machine, or crossover thrash bands such as D.R.I or Municipal Waste.