Song Spacing
Song spacing basically is the amount of silence between the end of a song and the start of another song. When mastering an album to be reproduced on tape vinyl or in these days mp3 and cds, a decision must be made as to how many seconds should pass before the next song starts.
Now this silence spacing might not apply if you have a song for example, that preludes into the next song without any silence at all. One good example of this off the top is Michael Jackson's two songs Speed Demon & Liberian Girl. There is no silence in between the start an ending of these songs so there in that case you just have to choose to cut at a certain position.
Songs that start or end abruptly, fades in or out, & dynamic beginnings can have the same amount of time spacing basically.
In all, the main importance of song spacing is to make sure the listener knows that a song has ended and a new songs has started. If the space is too long for example a person may think, what the heck happen?, hey is the album over?, that was just 2 songs.
So it is important to have a comfortable spacing that gives a smooth transition from song to song.