Library compositions ideally need to get to the meat of the song quickly and capture the attention of the listener within a few seconds. Put yourself in an editor’s shoes – they may have to listen to possibly over 20 songs in a hurry. So, no lengthy or drawn-out DJ intros.
Compositions need to have a definite ending on all versions, so no fade-outs. It is better to build up to a high than to completely slow things down towards the end.
It is advisable to have slight changes every 8 bars, like a different subtle instrument added or something rhythmical. These changes do not need to be dramatic; their purpose is to keep the song varied, continually evolving and interesting. The choruses should have slightly different elements in them too. This will give the editor more instant choices, giving your songs more chances of getting used, more often.
It’s best to maintain a theme throughout a song which the editor can dip in and out of, several dramatic changes are not advisable.
Rhythmical patterns of all types of genres are often used as underscores and are therefore essential to pay attention to.
Like the theme, the main instrumentation of the song should remain consistent throughout. If a piano is the basis for the first part of a song, and a guitar for the second part, it will be more difficult for editors to work with.