Passwords (Bob Dylan song titles):

Level 5:   WATCHTOWER
Level 7:   ROLLING STONE
Level 9:   HURRICANE
Level 11:  BLOWIN
Level 13:  TAMBOURINE
Level 15:  KNOCKING
Level 17:  HEAVEN
Level 19:  CHANGING
Level 21:  DESOLATION
Level 23:  BLONDE
Level 25:  RAIN
Level 27:  SIMPLE TWIST
Level 29:  FOREVER YOUNG
Level 31:  DIGNITY
Level 33:  VISIONS
Level 35:  SUBTERRANEAN
Level 37:  POSITIVELY
Level 39:  TANGLED UP
Level 41:  JOHANNA
Level 43:  MOZAMBIQUE
Level 45:  SARA
Level 47:  ISIS
Level 49:  DESIRE