The four tones of Chinese poetry and dialectology (simplified Chinese: 四声; traditional Chinese: 四聲; pinyin: sìshēng) are four traditional tone classes of Chinese words. They play an important role in Chinese poetry and in comparative studies of tonal development in the modern varieties of Chinese, both in traditional Chinese and in Western linguistics. They correspond to the phonology of Middle Chinese, and are named even or level (平 píng), rising (上 shǎng), departing or going (去 qù), and entering or checked (入 rù). (The last three are collectively referred to as oblique 仄 (zè), an important concept in poetic tone patterns.) They were reconstructed as mid (˧ or 33), mid rising (˧˥ or 35), high falling (˥˩ or 51), and mid (˧ or 33) with a final stop consonant respectively. Due to historic s