Apsaras are beautiful, supernatural women. They are youthful and elegant, and proficient in the art of dancing. They are the wives of the Gandharvas, the court servants of Indra. They dance to the music made by their husbands, usually in the palaces of the gods, and entertain gods and fallen heroes. Apsaras are said to be able to change their shape at will, and rule over the fortunes of gaming and gambling. Urvasi, Menaka, Rambha and Tilottama are the most famous among them. Apsaras are sometimes compared to the muses of ancient Greece, with each of the 26 Apsaras at Indra's court representing a distinct aspect of the performing arts. Apsaras are associated with water; thus, they may be compared to the nymphs, dryads and naiads of ancient Greece. They are associated with fertility rites.