Given the previously mentioned issues with Thai sheet music, I asked around friends who were more or less Thai traditional music experts to get some guidance. It turns out there is sheet music which has slightly more detail out there.
A perfect example can be found here:
http://www.sakamula.com/note.html
So what do all those dashes and vertical lines mean?
Thai music can be divided up into 8 rooms (ห้อง hawng3), and in each room there are four notes (โน้ต not4). For example:
|ดดมซ | – ซซล | ทดรม | – - – - | มรดล | ซลดม | ดรดด | – ดดด |
A dash symbol (-) can have two meanings. If it is followed right after a note, such as ซ- and ม- in the above example, it means you should extend that note twice as long. Instead of hitting it once, you hit it several times in rapid style. This is called a graw1 กรอ. This is regardless of the (-) being in the following room. In this video you can hear both single notes and graw’d notes:

If you see multiple dashes together, it’s a pause.
So how does the ching conductor come into play? Well, there are three different styles – each appropriate for different types of traditional Thai music. Each style is defined by the number of levels, or ชั้น chan4.
3 Levels สามชั้น – The slowest ช้าสุด.
With the first style, the ching beats at the end of every other room as so:
| – - – - | – - – ฉิ่ง | – - – - | – - – ฉับ | – - – - | – - – ฉิ่ง | – - – - | – - – ฉับ |
4 Levels สี่ชั้น – Medium speed เร็วขึ้น.
With this style, the ching beats at the end of each room as so:
| – - – ฉิ่ง| – - – ฉับ| – - – ฉิ่ง| – - – ฉับ| – - – ฉิ่ง| – - – ฉับ| – - – ฉิ่ง| – - – ฉับ|
1 Level หนึ่งชั้น (ชั้นเดียว)– Fastest speed เร็วสุด.
This style is meant for the fastest of music and has the ching beating with every other note:
| – ฉิ่ง – ฉับ| – ฉิ่ง – ฉับ| – ฉิ่ง – ฉับ| – ฉิ่ง – ฉับ| – ฉิ่ง – ฉับ| – ฉิ่ง – ฉับ| – ฉิ่ง – ฉับ| – ฉิ่ง – ฉับ|
A section of music is called a tawn3 ท่อน. Music is often divided into sections when certain parts are repeated (like the chorus, for example).
A practice sentence for the more advanced learners:
Thai music has 8 rooms, and 4 notes per room.
Don1dtree1 thai1 mee1 baed2 hawng3 hawng3 la4 see2 not4
ดนตรีไทยมี 8 ห้อง ห้องละ 4 โน้ต

