A "Topline" writer is the word used to describe someone who writes the vocal tune and the lyrics. I'm not sure where that name originated but it seems to have stuck and is now a standard within the songwriting community.
There is a whole industry ready to match Topliners with producers (who only make instrumentals).
So, how do you get into Topline writing?
There are music publishers and management companies which represents record producers and artists. If you get in contact with these companies, be sure to make clear that you are a Topline writer and available to work with producers. Good Topliners will be able to walk into a studio and come up with a song on the spot (taking a couple hours to write and record vocals).
But what if you can't sing but enjoy writing lyrics and vocal melodies? A great way to get your music developed is to ask a talented music producer to create a piece of music (in a suitable style) so that you can write your song to it.
The advantage of writing to an existing instrumental (or beat) is that it is often easier and cheaper for a producer to create a piece of music from scratch. Also, it's easier to write a vocal melody (and lyrics) to a completed instrumental because you have the final feel of the music to inspire you.
Check out the winner of our topline writing competition here