How are notes arranged from left to right on a standard keyboard?

On a standard keyboard, such as that of a modern piano, notes are arranged in ascending order of pitch from left to right.1

The keys are organized into a repeating pattern of white keys, which represent diatonic notes, and raised black keys, which represent the corresponding sharps and flats. This layout, which became standardized in the 15th century, ensures that as a player moves toward the right side of the instrument, the strings struck by the hammers become shorter and thinner, resulting in higher-pitched sounds. Conversely, the keys on the left end of the keyboard correspond to longer, thicker strings that produce lower-pitched sounds.231

While the number of keys and the specific range of the keyboard have evolved over time, the modern standard consists of 88 keys, spanning seven octaves and a third. The visual distinction between white and black keys was not standardized until approximately 1800, having previously varied based on regional fashion and the materials used, such as ivory or ebony.45