ASCAP related publishing entity that was earlier a subsidiary, or under the ownership of the Atlantic Recording Corporation.
Later on when Atlantic was brought together with Warner Bros. as part of the Warner Music Group publishing details seem to have been taken over by Warner/Chappell Music, Inc.

Sometimes printed as Walden Music, Inc. on releases.
Please consider also Walden, Walden Music, Walden, Inc or Walden Music Corp., when credited that way on release.