Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Singing in a dream is false speech and amusement. Beautiful singing indicates a profitable trade. Ugly singing indicates a losing trade. Singing in the market indicates a scandal for the poor and a loss for the rich.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Singing indicates dispute and evil. Whoever sees himself singing falls into strife. The singer is a wise man or scholar who distracts people from the Hereafter.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Singing is interpreted as falsehood and worry. Hearing it indicates hearing false news. Whoever sees himself singing to himself will be afflicted with worry and sadness.