The responsibilities of the music publisher are varied and complex. Here is a general overview of a publisher's duties, and what they mean to you, the songwriter.
The activities of the music publisher can be said to fall into four categories: Creative, promotional, business, and administrative.
Creative duties include listening to new songs; going to clubs and recording studios to hear and meet new artists;
working to develop up-and-coming writers; producing demos; pairing writers with other writers or producers; finding new uses for songs already in their catalogue.
Promotional activities include finding out what songs are needed by producers, managers and A&R reps for their artists; scouring the trade magazines and tip sheets to find new projects that may need new songs;
sending out demos to producers and artists' managers; keeping track of which producers are holding which songs, and which songs they liked and disliked.
Business activities include hiring personnel, negotiating contracts with writers, producers, artists and managers;
granting licenses, and maintaining contacts with foreign sub-publishers.
Administrative duties include filing copyright forms; filing notices with the Performing Rights Organisations; collecting mechanical royalties from record companies, or filing notices with agencies to collect for them; general accounting chores; paying writer royalties.
There are other activities reserved for some of the larger publishing companies. These are the companies who can afford to buy the catalogues of major income-generating writers from other large publishers.
One such activity is the Publishing Development Deal.
This is very appealing to a lot of artists as it allows them to quit their day job and focus 100% on their music.
In this situation a publisher acts like a manager, producer, A&R person and publicist in one.
Major music publishers will sign writer/artists that they believe in to publishing development deals. They might offer an advance of $20,000 to $30,000 for a one-year deal with the option to renew, in the hope that they can secure a record deal.
They might then pair the artist with other writers to write the best songs possible, and pay for a master quality recording that they will use to shop the artist to record labels.
In addition they will set up live showcases, and put together press kits.
Of course, if they do get a record deal they will own half to all of the publishing rights to all of the songs the artist records.
Usually there is no reversion clause for this kind of contract, because the publisher is making a big investment in the writer/artist with no guarantee of future success.
Another activity major publishers might engage in is the hiring of Staff Writers.
Staff songwriters usually receive a weekly salary, treated as a recoupable advance against future royalties. Or they may be paid on a work-for-hire basis, with each song written being owned and copyrighted by the publisher (employer). This is usually the case with new writers.
When looking to work with a music publisher, it's important to know exactly what your goals are, so you know exactly what to ask for.
For more on this check out Making Music Make Money by Eric Beall