Generally, this is an artist or producer decision. Assuming that each song will start almost immediately, the gaps can be determined simply by how much silence is rendered into the audio file at the end of each song.

This is the best way of ensuring you have the desired amount of space between songs based on your music and taste.

Alternatively, gaps can be extended or reduced by the mastering or cutting engineer.

For a vinyl cut the tracks are arranged in order and rendered as one long audio file for each side known as a ‘Compiled Side’. At this point you can request extra space between songs if required.

No, the visible gaps are simply a marker showing where each song starts and finishes. To do this the pitch of the cutting head is sped up for less than a second to momentarily increase the land between the grooves. Without a visible space between tracks, it would be very difficult to drop the playback stylus on your favourite song. 

A neat trick is to add an extended gap after the final song on an album, usually up to 1 minute, and feature some special content to surprise your listeners. This could be the classic ‘hidden track’, bonus audio or even a personal message to your fans.

A few notable examples include:

• The song *‘2013’* by the Arctic Monkeys. A hidden bonus track on the Japanese release of their fifth studio album *‘AM’* (2013).
• *Nevermind* by Nirvana (1991) includes *“Endless, Nameless”*, which appears after several minutes of silence at the end of the album.
• *‘Her Majesty’* by The Beatles (1969), a hidden song that appears at the end of *Abbey Road* twenty seconds after, you guessed it… *‘The End’*.
• Bowling for Soup’s *‘Drunk Enough to Dance’* (2002) includes a hidden track called *‘Belgium (Acoustic)’*.
• And the heartbeats—unlisted hidden audio that appears and fades away at the end of the seminal electronic album *‘Leftism’* by Leftfield (1995).