吳兆基先生的良宵引 Master Wu Zho-ji's playing of Liang Xiao Yin (Song of a Pleasant Night)
鋼絃 Metal String
管平湖先生的良宵引 Master Guqn Ping-hu's playing of LXY
絲絃 Silk string
Above two images shows my study of Master Guan's palying, against Wu Zhizhai Qin book (from Qin Dynasty edited in 1722). (copyright @ Peiyou Chang)
Listen to Master Guan's playing, I feel that I can sense his way of moving his left hand, as if one is writing Chinese calligraphy. There are yin and yang interacting movement.
If the movement is going to the rightward direction, for example, the brush will start with a leftward movement.
If the movement is a downward direction, the brush will start with an upward movement.
Compare Master Wu's playing against the Wu Men Qin Book, I found that there are several "nao" that noted in the notation, but Master Wu's recording hear no "nao."
若"打圓" 吳老為兩下共四聲, 管先生多為三下共六聲
The technique "da-yuan," Master Wu played two times total 4 sounds, and Master Guan mostly played three times, total 6 sounds.
Master Guqn and Master Wu has very different style of qin playing
Master Guan is energetic and vigorous. Yin and Nao (two ways of vibrato) are more easily to distinguish.
Master Wu is more reserved, clean, yet energetic. Yin and Nao are more unforthcoming and not easily to distinguish.