Music publishers and licensing houses are two very different types of company. Approaching directly can work, but before sending in music to either type of company, do as much research on the recipient as much as you can. Most important here is to make sure that the person you are targeting is the right person. This means that the person actually deals in the type of music you want to send them. Approaching indirectly is best done by going through someone who has existing relationships with the publishers and sync/licensing agencies. In my experience, this is the best approach. Some publishers don’t like to take unsolicited material, or they are very busy – so having a trusted colleague suggest music can carry a lot more weight.
Many people worry that their songs that aren’t perfectly mixed and mastered. Though this is more of an issue with sync companies who may need a more finished product, publishers who are looking for songs are less worried. The aim should be to represent your material in the best possible manner.
Sync and licensing houses differ from publishing houses in this aspect because they are turning around tracks at a much faster rate.
Clients are requesting certain types of music for certain projects with deadlines etc and therefore the sync or licensing companies will find it much easier to place tracks that are ready to go – ie that have been mixed and mastered etc.
Publishers have a much more nurturing role than sync companies, but dont be afraid to submit music to sync companies if its not mixed in an expensive studio etc, its totally possible to get music placed that has glitches or doesn’t sound super polished. This is sometimes viewed as character or vibe and can give your music some authenticity.