Five musicals have been shortlisted from 144 entries for the 14th annual Vivian Ellis prize, which was set up to encourage new writing.
Short extracts will be performed by a cast of professionals. And the works will be judged by a panel including Sir Tim Rice, Don Black, who wrote the lyrics for Sunset Boulevard, the choreographer Arlene Phillips and Joel Grey, one of the stars of Chicago.
The successful writer will hope to emulate the success of former prize- winner Charles Hart, the lyricist for The Phantom of the Opera.
Chris Grady, the prize's administrator, said: "There is no support and no training for people who want to write musicals. So the prize is absolutely vital."
Nearly every performer who was asked agreed to take part. Mr Grady said: "They're all looking for future roles. For Gary Wilmot, exciting though it is to be going into Oliver! as Fagan, it is even more exciting if he can help a writer create a new role for him."
Among the shortlisted lyricists/composers are Alex Loveless, the youngest finalist at the age of 21, and Steve Nimmon, 32, a primary school teacher from Co Antrim.
There will be a public performance of the works on Thursday.