WASHINGTON — The Library of Congress unveiled an extensive plan Wednesday to help libraries and archives nationwide preserve recorded sound to guard against losing historic recordings as has occurred with those by George Gershwin, Frank Sinatra, and Judy Garland.

About 14,000 public and private institutions hold sound recordings, according to one survey. The plan carries 32 recommendations as a blueprint to coordinate their efforts and enlist commercial recording studios and private copyright holders in preservation efforts. Congress called for a plan in a 2000 law to preserve recordings.