I recommend two genres of Thai music: Classical Thai (
เพลงไทยเดิม) and first generation foreign-inspired Thai music (
เพลงไทยสากล), primarily that of Suntaraphorn (
สุนทราภรณ์).
Let me show you some examples. Perhaps the most famous of the classical variety is "
เขมรไทรโยค" and there are two versions. The first is in original classical style sung accompanied by original instruments:
https://www.youtube.com/watch?v=N1MxlazvN_YThe second is the same song, but adapted for modern tastes:
https://www.youtube.com/watch?v=xpl_ZwBg_TAI encourage you to listen to these songs all the way through. The lyrics describe a trip through nature; the melody is haunting.
A second song from this genre is "
ลาวดวงเดือน". Listen to this song at
https://www.youtube.com/watch?v=o1fEEVhNg64As for the second genre, the songs of Suntaraporn, there are hundreds, as well as songs by other composers in the style of Suntaraporn. You can hear that some are sung in the style of the 1940's while other versions are sung in a more modern voice Here are some examples:
https://www.youtube.com/watch?v=RffkzF3Vuvchttps://www.youtube.com/watch?v=t5koJ_IDS4shttps://www.youtube.com/watch?v=iq8XIMF ... GoblOh3Vznhttps://www.youtube.com/watch?v=5OkDc1KeeSghttps://www.youtube.com/watch?v=duwK4UbzxWM (a Thai tango)
https://www.youtube.com/watch?v=RKZYyoVMvWghttps://www.youtube.com/watch?v=IocyuI_0vwEAre these the types of songs you are looking for?