Source: The Great Interpretation of Dreams (Ibn Sirin)
Singing with a beautiful voice in a dream indicates a profitable trade or a position and a word that is heard.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Singing with a beautiful voice indicates joy, good tidings, and good news.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Singing with a beautiful voice is interpreted as goodness. Whoever sees himself singing with it will attain goodness.