Question: What was the musical genre of the Greatest Hits compilation?

Context paragraphs:
Ritchie Valens...His Greatest Hits Volume 2: Ritchie Valens...His Greatest Hits Volume 2 is the second greatest hits compilation by Ritchie Valens.  This follow-up to the "Ritchie Valens Memorial Album/His Greatest Hits" includes Valens' last two charted singles and ten tracks from the three original albums.  Three tracks were previously issued on the first greatest hits package: "Donna", "La Bamba" and "Cry, Cry, Cry"

Greatest Hits: Straight Up!: Greatest Hits: Straight Up!  is the second greatest hits compilation by singer Paula Abdul.  The album was released on May 8, 2007.  The album contains Abdul's 6 U.S. number-one singles.  This compilation also includes the top-20 single "Will You Marry Me? " which was left off her 2000 album, but excludes the previously unreleased track "Crazy Love".  Like its predecessor album, "Greatest Hits: Straight Up!"  did not chart on the "Billboard" 200 (though it did chart near the bottom of the R&B Albums chart).  As well as containing Abdul's hits, it includes the "Head Over Heels" album tracks "If I Were Your Girl" and "It's All About Feeling Good".

Greatest Hits (Eternal album): Greatest Hits is the first compilation album by the British girl group Eternal, released in October 1997.  The album contains their fourteen consecutive Top 15 hit singles, which at the time was an unprecedented record for a British girl group.  Louise Nurding's vocals appeared on the album, however she was not featured on the cover.

Demons (Fatboy Slim song): "Demons" is a song by English big beat musician Fatboy Slim, featuring Grammy Award-winning American R&B-soul singer Macy Gray.  The song was released as a single from Slim's 2000 album "Halfway Between the Gutter and the Stars", and later appeared on Gray's 2004 greatest hits compilation "The Very Best of Macy Gray" as well as Slim's 2006 greatest hits compilation "The Greatest Hits - Why Try Harder".  It contains elements of Bill Withers' 1973 song "I Can't Write Left-Handed".  The gospel group The Blind Boys of Alabama covered the song on their 2005 album "Atom Bomb".  Recently, the song was featured in the Netflix series Sense8.

Louise Redknapp: Louise Elizabeth Redknapp (née Nurding, born 4 November 1974), professionally known as Louise, is an English singer and media personality.  She was a member of Eternal, an R&B girl group which debuted in 1993 with their quadruple-platinum studio album "Always & Forever".  In 1995, Redknapp departed the group for a solo career, in which she released the platinum-selling albums "Naked" (1996), "Woman In Me" (1997) and "Elbow Beach" (2000).  Redknapp has sold over 15 million records in her home country, the United Kingdom.

Greatest Hits, Vol. 3 (Johnny Cash album): Greatest Hits, Vol.  3 is a greatest hits compilation by country singer Johnny Cash, released on Columbia Records in 1978 (see 1978 in music).  It is the third and last part of the Johnny Cash "Greatest Hits" compilation series; the previous parts, "Greatest Hits, Vol.  1" and "Greatest Hits, Vol.  2", had been released in 1967 and 1971, respectively.

Hits from Yesterday &amp; the Day Before: Hits from Yesterday & the Day Before is a greatest hits compilation album by Barenaked Ladies which includes most of the band's US singles released from 1997 to 2010.  The album was originally planned to be released on September 13, 2011, then September 20, 2011, but it was finally released on September 27, 2011.  The fourteen-track standard edition does not include any new material, although it is the first time "The Big Bang Theory Theme" appears on an album.  This is the second greatest hits compilation from Barenaked Ladies, after 2001's "".

The Black Sessions: The Black Sessions is a 3-disc (2 CD greatest hits / double album, 1 DVD live album) compilation, from the band, Katatonia.  It is the band's second greatest hits album, the previous being "Brave Yester Days".  The "greatest hits" portion, features the second half of the band's musical genre change of alternative rock & gothic rock, that started from "Saw You Drown", while previously they had an alternative metal, gothic metal & doom metal style prior to "Saw You Drown" and a style that is only present of the final song this compilation.

Crazy for You (Madonna song): "Crazy for You" is a song by American singer Madonna from the soundtrack album to the 1985 film "Vision Quest".  It was released on March 2, 1985 by Geffen Records as the first single from the soundtrack.  The song appears remixed on the greatest hits compilation "The Immaculate Collection" (1990) and was re-released on February 24, 1991 by Sire Records to promote the album.  The song was also included on the ballads compilation "Something to Remember" (1995) and the greatest hits compilation "Celebration" (2009).  Producers Jon Peters and Peter Guber, along with music director Phil Ramone, decided to use Madonna after listening to her previous recordings, employing John Bettis and Jon Lind to write the song.  After reading the script of the film, Bettis and Lind wrote the song about the situation in which the lead characters meet at a nightclub.  Initial recording sessions did not impress Bettis and Lind, and they felt that "Crazy for You" would be dropped from the soundtrack.  However, a new version was recorded to their liking.

The Greatest Hits Collection II: The Greatest Hits Collection II is the second greatest hits compilation album by country music duo Brooks & Dunn.  It is the sequel to the duo's 1997 compilation "The Greatest Hits Collection".  It is also the second collection of the duo's most popular releases, chronicling their greatest hits from 1998's "If You See Her" to 2003's "Red Dirt Road", omitting songs from 1999's "Tight Rope".  Three new recorded tracks — "That's What It's All About", "It's Getting Better All The Time", and "Independent Trucker" — are also included on this compilation.  These first two songs were released as singles, peaking at #2 and #1, respectively, on the "Billboard" Hot Country Songs charts.  The album is currently out of print.

Supporting paragraphs: Greatest Hits (Eternal album) Louise Redknapp
Answer: R&B girl group