The music of Thailand includes a wide array of distinct genres, both traditional and modern.

Traditional Thai musical instruments are varied and reflect ancient influence from far afield – including the klong thap and khim (Persian origin), the chakhe (Indian origin), the klong chin (Chinese origin), and the klong khaek (Indonesian origin).

The two most popular styles of traditional Thai music are luk thung and mor lam. The latter in particular has close affinities with the music of Laos.

Aside from the Thai, ethnic minorities such as the Lao, Lawa, Hmong, Akha, Khmer, Lisu, Karen and Lahu peoples have retained traditional musical forms.

Though Thailand was never colonized by colonial powers, pop music and other forms of modern Asian, European and American music have become extremely influential.

Thai classical music is synonymous with those stylized court ensembles and repertoires that emerged in their present form within the royal centers of Central Thailand some 800 years ago. These ensembles, while being influenced by older practices and repertoires from India, are today uniquely Thai expressions. While the three primary classical ensembles, the Piphat, Khrueang sai and Mahori differ in significant ways, they all share a basic instrumentation and theoretical approach. Each employs small ching hand cymbals and krap wooden sticks to mark the primary beat reference. Thai classical music has had a wide influence on the musical traditions of neighboring countries. The traditional music of Myanmar was strongly influenced by the Thai music repertoire, called Yodaya (ယိုးဒယား), which was brought over from the Ayutthaya Kingdom. As Siam expanded its political and cultural influence to Laos and Cambodia during the early Rattanakosin period, its music was quickly absorbed by the Cambodian and Lao courts. As Frédéric Maurel explains: "From the close of the eighteenth century and through the nineteenth century, a number of Khmer pages, classical women dancers, and musicians studied with Thai ajarn (masters or teachers) in Cambodia. The presence of this Thai elite in Cambodia contributed to the development of strong Thai cultural influence among the Khmer upper classes. Moreover, some members of the Khmer royal family went to the Thai court and developed close relations with well-educated Thai nobility, as well as several court poets. Such cultural links were so powerful that, in some fields, one might use the term 'Siamization' in referring to the processes of cultural absorption at the Khmer court at that time."

Several kinds of small drums (klong) are employed in these ensembles to outline the basic rhythmic structure (natab) that is punctuated at the end by the striking of a suspended gong (mong). Seen in its most basic formulation, the classical Thai orchestras have a very strong influence on the Cambodian (Khmer) pinpeat and mahori ensembles, and are structurally similar to other orchestras found within the widespread Southeast Asian gong-chime musical culture, such as the large gamelan ensembles of Bali and Java, which most likely have their common roots in the diffusion of Vietnamese Dong-Son bronze drums beginning in the first century.

Traditional Thai classical repertoire is anonymous, handed down through an oral tradition of performance in which the names of composers (if, indeed, pieces were historically created by single authors) are not known. However, since the beginning of the modern Bangkok period, composers' names have been known and, since around the turn of the century, many major composers have recorded their works in notation. Musicians, however, imagine these compositions and notations as generic forms which are realized in full in idiosyncratic variations and improvisations in the context of performance.