adjective (a)

• lacking interest in or talent for music(adj.all)

  Example:
  Too unmusical to care for concerts.
  

  Synonym:
  nonmusical
  

  source: wordnet30
• not musical in nature(adj.all)

  Example:
  The unmusical cry of the bluejay.
  

  Antonym:
  musical
  

  source: wordnet30
• lacking melody(adj.all)

  Synonym:
  unmelodic, unmelodious
  Antonym:
  melodic, melodious, musical
  

  source: wordnet30