Indeed, copyright, like many other types of property, can be licensed by the owner to others for commercial gain.  As copyright is a private right, it is up to you and your potential licensees to negotiate the terms of the licence.

IPOS conducts complimentary IP Business Clinics for Singapore citizens, Permanent Residents and Singapore registered businesses to seek advice from a professional consultant on strategies and options for leveraging on IP assets, including licensing strategies.

You may find out more and register for a session here.