If you dream of entering a ballroom where people seem happy and the music is pleasant, your attempts to achieve happiness will be successful. Be sure that you keep an open mind about what life has to offer. However, if the ballroom was empty, or unpleasant and dirty, or you were upset by the music or the people there, then your dream signifies financial troubles and/or arguments with authority figures.
If everyone in the ballroom was waltzing in unison, you need to get in touch with your inner spirit.... My Dream Interpretation
To see the waltz danced, foretells that you will have pleasant relations with a cheerful and adventuresome person.
For a young woman to waltz with her lover, denotes that she will be the object of much admiration, but none will seek her for a wife.
If she sees her lover waltzing with a rival, she will overcome obstacles to her desires with strategy.
If she waltzes with a woman, she will be loved for her virtues and winning ways.
If she sees persons whirling in the waltz as if intoxicated, she will be engulfed so deeply in desire and pleasure that it will be a miracle if she resists the impassioned advances of her lover and male acquaintances. ... Ten Thousand Dream Interpretation