In the field of recorded music, a hidden track (sometimes called a secret track) is a piece of music that has been placed on a CD, audio cassette, LP record or other recorded medium in such a way as to avoid detection by the casual listener. In some cases, the piece of music may simply have been left off the track listing, while in other cases more elaborate methods are used. In rare cases a "hidden track" is actually the result of an error that occurred during the mastering stage of the record's production.
On indexed media such as compact discs, double-grooving cannot be used, but there are additional methods of hiding tracks, such as:
Similar to the above example, having the song as a separate unlisted track with its own index point.
Placing the song after another track (usually, but not necessarily, the last track on the album), following a long period of silence. For example, Nirvana's song "Endless, Nameless" was included as a hidden track in this way on their 1991 CD Nevermind, after 10 minutes of complete silence. Although it was not the first hidden track to use this technique, this hidden song gained significant attention.
Placing the song in the pregap of the first track, so that the CD must first be cued to the track, and then manually back-scanned; these are often referred to as Track 0 or Hidden Track One Audio (HTOA). A CD player will not play these tracks without manual intervention, and some models (including computers) are unable to read such content. On Super Furry Animals third album, Guerrilla, "The Citizens Band" is found in the pre-gap approximately 5 minutes before the beginning of track 1. The song's lyrics are printed on the interior of the cardboard outer sleeve of the CD - essentially rendering them inaccessible without taking the sleeve apart. See List of albums with tracks hidden in the pregap.
Placing the song in pregaps on other tracks on the album.
Using many short tracks of silence before the hidden track. On Lazlo Bane's debut album 11 Transistor the eleventh song "Miday Train" is followed by 57 silent tracks 4 seconds each, with "Prada Wallet" (sometimes referred to as "The Birthday Song") being the 69th track on the album. The total length of silence between two songs is 3:48.
Hide the song in a mixed or distorted way which must be undone to play it. For example, on a DVD included with the deluxe and "ultra-deluxe" editions of Nine Inch Nails's Ghosts I-IV, two hidden bonus tracks ("37 Ghosts" and "38 Ghosts") are included as digital multitrack files, from which the songs may be reconstructed.
Often[when?] it is unclear whether a piece of music should be considered a hidden track. For example, "Her Majesty", which is preceded by fourteen seconds of silence, was originally unlisted on The Beatles' Abbey Road but is listed on current versions of the album. This is one of the first instances of a hidden track. The song snippet at the end of Sgt. Pepper's Lonely Hearts Club Band is considered by some to be a hidden track, by others to be noise not worthy of such a designation, and by others to be part of "A Day in the Life".
Aaliyah's self-titled album Aaliyah features the hidden song "Messed Up" on track 15. During the stages of the album creation Aaliyah had no desire to put this song on the album but after numerous inquiries from different labels and colleagues she decided on making it a hidden track.
In some rare cases, it is used to avoid legal issues. An example is Ramones' Loco Live American version, which has the song "Carbona Not Glue" hidden after "Pet Sematary" on track 17. It was originally recorded on their album Leave Home, but the makers of the spot remover Carbona, a registered trademark, objected. Therefore, reference to the song was removed from the album and cover.
"Freedom" by Paul McCartney was a hidden track on the original release of Driving Rain. It was later added as a track on the re-release. The track was not meant to be hidden; it was a tribute to 9/11 victims and McCartney wanted it on the album. The artwork was already done, so it was a hidden track.
"Train in Vain" by The Clash, which appears at the end of London Calling, was left out of the vinyl's track listing simply because it was a last-minute addition to the album, when the sleeves were already printed. It is thus not a real hidden track. It was originally intended as a promotional giveaway for NME. The later CD versions list the track on the sleeve.
Green Day's "All By Myself" (by drummer Tré Cool) was added as a secret song to Dookie due to the low sound quality of the original live recording.
"Weird Al" Yankovic's "Bite Me" from the album Off the Deep End was put on after ten minutes of silence to scare listeners who had forgotten to turn off the CD player. It was also a loose parody of "Endless, Nameless" by Nirvana. The cover of Off the Deep End is also a parody of the album containing that track, Nevermind, and its first track is a parody of that album's first track, "Smells Like Teen Spirit".
The X-Files: The Album, features a hidden track at 10 minutes and 13 seconds into the final track. The track consists of series creator Chris Carter explaining the series mythology and meaning behind the alien conspiracy. The hidden track even includes spoilers and minute details in the show's overall plot that had not yet been resolved on the show itself when the album was released. This track was included as both a surprise to devoted fans who would seek out answers in cross-promotional merchandise and as a mystery to new fans who would need to watch the show more closely to better understand the track.
The Jam's All Mod Cons does not list the song "English Rose" and its lyrics on original vinyl copies because Paul Weller believed the title and song lose meaning without accompanying music. They have been added to re-releases of the album.
Sometimes hidden tracks have become well known and received radio airplay, and occasionally climbed the charts.
The Beatles' track "Her Majesty" off their 1969 album Abbey Road is considered the first hidden track in recording history[by whom?]. The original pressings of Abbey Road did not list "Her Majesty" on the back cover song title listing, nor the record label; subsequent LP pressings and then CD issues were issued revealing the track. However, two years prior, in 1967, on the UK version of the Sgt. Pepper's Lonely Hearts Club Band album, there was the "inner groove" that appeared after "A Day in the Life" at the end of side 2. It was an unexpected, untitled, and uncredited Beatles recording – so this might be deemed a precursor to the hidden track. A potential hidden track on yet another Beatles album is on The Beatles (also known popularly as The White Album) 1968 double album. The hidden track is an unlisted, untitled and uncredited outro to "Cry Baby Cry" – more popularly known as "Can You Take Me Back", the primary lyrics of the song.
The Rembrandts had a sudden radio hit in 1995 with "I'll Be There For You", the theme song to Friends, so it was added at the last minute to their third album LP. As a result, the song was a hidden track on the early printing since the CD packaging had already been completed by the time the song was added. A sticker was however added to the outer shrink wrap advertising the song's inclusion.
"Skin (Sarabeth)" by Rascal Flatts, a hidden track from their 2004 album Feels Like Today, received enough airplay to chart in the Top 40 on the country charts, peaking at #2 in late 2005. In mid-2005, the album was re-issued with the song officially listed as a track, coinciding with the song's release as a single.