Having had the pleasure of staying in the Chao Phraya river area near the Saphan Taksin BTS station a few times in the last handful of years I've run into the khim (hammered dulcimer) player who frequents the walkway beneath the station, close to the central pier riverboat launch.
The khim as a stringed instrument, somewhat like a mini-piano without the keys. He uses two long sticks tipped with soft "feet" with a leather strip on one edge to gently strike the strings. There are 42 strings total, grouped into 14 bunches of three each.
If you've been in that area in the afternoon, you've probably heard him yourself. It's always a pleasant blend of traditional Thai music - at least I've never heard cocked an ear and said "Hey! That's "Wind Beneath My Wings"! - and he seems to collect a steady flow of coins as people pass by.