Thai and Cambodian music is diverse and varied, from traditional music to popular ballads, to modern boy and girl groups that are similar to western acts.

In Cambodia, traditional music groups have begun to thrive in recent years due to the growing tourist markets.

Thai traditional musical arts have been consistently maintained since the days prior to being called Thailand, back when the country was known as Siam.

This ability to maintain cultural history and connections is partly due to Thailand never being colonized by Western powers.  Although Thailand did come close to being taken over by several foreign powers, their leaders successfully signed treaties with the Japanese, the British and the Americans in varying capacities in order to keep out occupying forces. 

In the 1960s, both Thailand and Cambodia had thriving Rock and Roll music scenes.

https://www.youtube.com/watch?v=TUSTUjd8Bw8

The Vietnam Conflict derailed much of that western influence in Cambodia, as years of conflict spanned from the late 1960s to the 1990s.

In Thailand, what most locals call Thai country music, are probably closer to adult contemporary pop ballads here in the US.

Nowadays, Thai and Cambodian pop is exploding and both countries have music video channels. Plenty of hip-hop and pop influences from the West, but with their own Southeast Asian spin on those styles.