the a cappella vocal group The Song Spinners had a best-seller with "Comin' In on a Wing and a Prayer". In the 1950s, several recording groups, notably The Hi-Los and the Four Freshmen, introduced complex jazz harmonies to a cappella performances. The King's Singers are credited with promoting interest in small-group a cappella performances in the 1960s. Frank Zappa loved Doo wop and a cappella, so Zappa released The Persuasions' first album from his label in 1970. Judy Collins recorded "Amazing Grace" a cappella. In 1983, an a cappella group known as The Flying Pickets had a Christmas 'number one' in the UK with a cover of Yazoo's (known in the US as Yaz) "Only You". A cappella music attained renewed prominence from the late 1980s onward, spurred by the success of Top 40 recordings by artists such as The Manhattan Transfer, Bobby McFerrin, Huey Lewis and the News, All-4-One, The Nylons, Backstreet Boys, Boyz II Men, and *NSYNC. Contemporary a cappella includes many vocal groups and bands who add vocal percussion or beatboxing to create a pop/rock/gospel sound, in some cases very similar to bands with instruments. Examples of such professional groups include Straight No Chaser, Pentatonix, The House Jacks, Rockapella, Mosaic, Home Free and M-pact. There also remains a strong a cappella presence within Christian music, as some denominations purposefully do not use instruments during worship. Examples of such groups are Take 6, Glad and Acappella. Arrangements of popular music for small a cappella ensembles typically include one voice singing the lead melody, one singing a rhythmic bass line, and the remaining voices contributing chordal or polyphonic accompaniment. A cappella can also describe the isolated vocal track(s) from a multitrack recording that originally included instrumentation. These vocal tracks may be remixed or put onto vinyl records for DJs, or released to the public so that fans can remix them. One such example is the a cappella release of Jay-Z's Black Album, which Danger Mouse mixed with The Beatles' White Album to create The Grey Album. On their 1966 album titled Album, Peter, Paul and Mary included the song "Norman Normal". All the sounds on that song, both vocals and instruments, were created by Paul's voice, with no actual instruments used. In 2013, an artist by the name Smooth McGroove rose to prominence with his style of a cappella music. He is best known for his a cappella covers