Although you may or may not call yourself a "composer," whether you are a cabaret performer writing your own material or a studio musician who writes music, you have created art that needs care. Fortunately there are already several working programs to provide the basic services you will need.
StorageYou can deposit copies of your scores and recordings of your work at the American Music Center (AMC) in New York City. AMC will not accept originals or parts. You can have yourself identified in their listings as a composer with AIDS, if you like. AMC maintains a library for the public and links with other music libraries throughout the world.
Similarly, the New York Public Library for the Performing Arts accepts scores, recordings and any related materials for composers. It is vital that you speak with the Music Division curator as early as possible so that you know the correct procedure for donating your work. Because each organization collects differently, even if you deposit scores at the AMC, you might consider placing other materials, such as correspondence and papers, at the New York Public Library.
If you have no one you feel is appropriate (knowledgeable in your field and sympathetic to your work) to name as your representative, the American Composers Alliance (ACA) offers a Custodial Membership. This plan guarantees availability of your music for performance, publication or recording in the event of your death. There is a fee for this program, however, ranging from $750 to $4,000 based on the length of the service, which can be up to the full fifty years of copyright protection.
There is, of course, a difference between placing your work in an archive and having it actively promoted. If you have a representative knowledgeable in the music field willing to promote your work, it has a better chance of reaching an audience.
As a composer, you will not face the same extraordinary storage problems as visual artists. With some additional time and planning, you will be able to secure a safe and active home for your work.