罨hammer-on

Pinyin: yǎn

Left hand, pressing

Also written: 掩

The right hand does not pluck; a left finger strikes down on the string at the given position and the impact itself sounds the note.

How it is played

Usually after a stopped note: the finger already on the string (often the ring finger) stays put, and another finger (often the thumb) strikes straight down at the position above it (toward the bridge) and presses firmly at once. The impact sets the string vibrating and sounds the note at the striking finger. Thumb, middle and ring fingers can all do it. Strike fast, accurately and firmly, but do not knock the soundboard.

How it sounds

A stopped note, lighter than a plucked one, with a slight percussive edge.

In the classical handbooks

大中名三指俱有用罨法，以左指按絃得聲曰罨，不用右手彈絃也，須勿擊響琴面為妙。

Gist: Thumb, middle and ring fingers all use yan: sounding the string by the left finger's pressing is yan; the right hand does not pluck. Best not to let it knock the soundboard.

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

Which finger strikes, and where

Thumb, middle and ring fingers may all play yan: the left finger presses to sound the string and the right hand does not pluck. Source: Qinxue Rumen (Introduction to Qin Studies), vol. 1, left-hand pressing symbols(opens in a new window) · View the original page
After the ring finger stops and plucks, the thumb strikes the string at the next position above to sound it. Source: Yihe Qin Society, “Jianzipu: a short guide to technique symbols” (the common modern reading)(opens in a new window)
罨 and 掩 are different spellings of the same thumb-strike technique. Source: English Wikipedia, “Guqin playing technique”(opens in a new window)

Easily confused with

虚罨xū yǎn· hammer-on from silenceIf the string has just been plucked and yan follows, it is yan; if the string has not been plucked beforehand, it is xu yan.
掐起qiā qǐ· left-hand pull-off to a stopped noteQia qi sounds the string by the thumb hooking it; yan sounds it by striking down.