淌drift down

Pinyin: tǎng

Left hand, sliding

Also written: 淌下, 尚

Let the still-unsettled ring slide slowly downward, like water running down a slope.

How it is played

Having sounded a note at a higher position (often the one just reached), and before it settles, keep pressing and let the finger slide with the string's momentum toward the tail nut, carrying the sound down. Scores often borrow 尚 for 淌. The slide must be continuous and unbroken, slower than an ordinary xia.

How it sounds

A continuous descent in pitch with a clear portamento and a long tail.

In the classical handbooks

乘其上一位之音未定，即帶其音而拖下也。

Gist: While the note at the position above is not yet settled, carry it along and drag it down.

Qinxue Rumen (Introduction to Qin Studies) · 卷上·左指按法字母 · Qing dynasty, 1864 · View the original page · View source

Where sources disagree

Speed of the drift, and whether vibrato is added

While the note at the position above is still unsettled, carry it along and drag it down. Source: Qinxue Rumen (Introduction to Qin Studies), vol. 1, left-hand pressing symbols(opens in a new window) · View the original page
Close to xia but slightly slower and with a slide; seen mostly in the lower register. Source: Yihe Qin Society, “Jianzipu: a short guide to technique symbols” (the common modern reading)(opens in a new window)
Slowly down, like water running off. Source: 《梅庵琴谱》（据Guoqinwang, Guqin Da Cidian (Great Dictionary of the Guqin)所录原文）(opens in a new window)
After sounding at the ninth hui, the thumb drifts finely down to the tenth, or back to the home position; this is also called tang yin. Source: 《荻灰馆琴谱》（据Guoqinwang, Guqin Da Cidian (Great Dictionary of the Guqin)所录原文）(opens in a new window)

Easily confused with

淌吟tǎng yín· vibrato drifting downTang yin adds vibrato while drifting down; tang is just a slow downward slide, with or without vibrato.
下xià· slide downXia is about reaching the new position; tang is about the descent itself.