If you are singing alone, you are being urged to become independent and if you are singing in a choir or with a group of people, you are being urged to interact more socially.
If you are a singer in waking life, your dream will be expressing your waking preoccupation with music. Singing is also an act of worship and an important part of many belief systems
A football anthem, for example, will suggest camaraderie and encouragement, whilst if the type you are doing is more akin to chanting suggests that you may be in touch with a higher vibration or your inner wisdom, especially if the chanting is a mantra. Dreaming of singing the blues could reflect your real-life sense of melancholy.
If the lyrics of the song are clear, pay attention to them and see how they apply to your waking circumstances.
See also ARTS AND CRAFTS.