To dream of celestial signs, foretells unhappy occurrences will cause you to make unseasonable journeys. Love or business may go awry, quarrels in the house are also predicted if you are not discreet with your engagements. See Illumination.... Ten Thousand Dream Interpretation
Vision: Singing a song: right now you are at peace and happy. Hearing a choir: many meaningful hours ahead. Hearing or singing a happy song: expect good news. Hearing a sad song: bad news. Singing a sad song: you’re melancholy and you worry too much.
Depth Psychology: Singing means that you are at peace with yourself and the world around you.
A song in a dream: you are remembering past experiences and emotions. Was the song sad or happy? See Music, Song, Yodeling.... Dreamers Dictionary
The signs of the zodiac carry different meanings based on their depiction. Frequently they represent aspects of your personality that are not wholly known or acknowledged, and therefore need developing.
For example, dreaming of Virgo may represent your need to reconnect with feminine attributes or clean up your act physically (Virgo is the virgin). Here are some other sample correspondences which may be expanded by reading any good astrology text:
Aquarius: Erratic creative energy; feelings of unrest.
Aries: Quick decisions that may not be wise; courage and zeal for things to which you commit yourself.
Cancer: Paradoxical actions that others find confusing.
Capricorn: A cool, patient temperament that hides deeper passions.
Gemini: A restless, artistic nature; often impedes meeting goals due to getting bored or distracted.
Leo: Strong leadership skills always need to be tempered with wisdom so that you don’t become boastful or pompous.
Libra: The need for balance, especially with the emotions.
Pisces: A strong spiritual nature is starting to develop along with a new sense of responsibility.
Sagittarius: The mark of an overachiever. Make sure your goals are reasonable.
Scorpio: A bold, determined nature that sometimes “stings” to achieve its goals or communicate a vision.
Taurus: Watch your temper and tendency to want “things” to fill up vour life.... The Language of Dreams