These commentators projected into the CT past the cultural significance and semantics of terms of their times. They were often divorced from other cultural domains such as music, dance, etc. (The anecdote involving U.V. Swaminatha Iyer and his teacher Meenakshisundaram Pillai regarding the former learning Carnatic music exemplifies this.)  Often when the traditional Tamil scholars interpreted key terms dealing with such fields, they were wrong. An example is the case of the word kāmaram, which occurs in a CT text. Traditional commentators interpret the term as a specific melody by the name cīkāmaram. See http://www.tamilvu.org/slet/l1100/l1100pd3.jsp?bookid=20&auth_pub_id=68&stpage=157&edpage=157&file=l1130704.htm&id=2&word=தும்பி . You will find the same interpretation parroted by other commentators with respect to the occurrence of the same word in later texts too. See http://www.ifpindia.org/ecrire/upload/digital_database/Site/Digital_Tevaram/U_TEV/VMS1_047.HTM#p3 . This interpretation of kāmaram as cīkāmaram is as silly as equating the word rāga with Śrīrāga, a specific melody, and reflects these commentators' ignorance of epigraphic evidence of the use of the word kāmaram. In inscriptions we find an expert musician is often given the title kāmarap pēraraiyan which indicates kāmaram referred to melodious music in general. Most Tamil professors in Tamil Nadu will be unable to explain the term paṇṇuppeyarttal (modal shift of the tonic) that occurs in CT texts. To understand such terms one has to use musicological works such as Tamiḻicaik Kalaikkaḷañciyam by V. P. K. Sundaram. 

Similarly for the word paṉuval which meant 'warp' in specific poems, the traditional scholars assigned the meaning 'cotton' even though the meaning 'warp' is there in the oldest lexical work Tivākaram. They also failed to realize that the bards and warriors were not from two different strata of the society. Even as late as 11th century, as a Tanjavur temple inscription reveals, several performing artists were members of highly selective units of the Cōḻa army. 

Most of the Western scholars' interpretations/translations of CT texts are based on the interpretations of the above-mentioned traditional Tamil commentators. As a result, one has to be careful in reading the Old Tamil texts. In other words, considerable work needs to be done using tools of philological, linguistic, and historical analysis to understand the CT texts to excavate the culture that lies behind layers of traditional misinterpretation. Unfortunately, many Tamil literary scholars in Tamil Nadu do not know history, many historians do not know literature, and even if one knows both literature and history, one does not know linguistics. 

Regards,

Palaniappan