Synonyms for Unsung (same or very similar meaning)
WordNet sense 1 (not famous or acclaimed):
obscure, unknownWordNet sense 2 (not bringing honor and glory):
dishonorable, ingloriousWordNet sense 3 (having value that is not acknowledged):
unappreciated, unvaluedWordNet sense 4 (not recognized or admitted):
unacknowledgedFrom the ODE community, based on WordNetadd/edit