Arthur Schopenhauer thought of music as the greatest of the art forms because it and it alone; rather than being merely a copy of the Platonic Ideas, was a copy of the will itself, the metaphysical foundation of the world. Kierkegaard also saw music as the highest art form, but this was because he thought it was the only medium capable of representing the most abstract idea (the sensual) which in turn meant that the musical composition was unlikely to be repeated since it had already acquired its perfect expression.
Uncertainty, in common parlance, is a state in which an individual is unsure whether some proposition is true or not. It ultimately, therefore, arises from a lack of information. If we knew everything, like God, if he existed, or had access to a super-AI, like that some technophiles dream about, we would never find ourselves in a position of uncertainty. Moreover, if we could make decisions from a position of absolute certainty, we would be able to eliminate the suffering and/or anxiety that sometimes accompanies our decision-making.