What makes one refer to Carnatic music as “classical or art music”?

Tyagaraja worried about many things — about the death of brahmanatva — the lofty way of thinking and living, of sham religiosity, of sycophancy, of Lord Rama’s reluctance to bestow grace. In one such song in the poignant raga Naganandini, he laments: sattaleni dinamunu vacchena

But he did not worry for music except that it should not be divorced from bhakti. […]

What makes one refer to Carnatic music as “classical or art music”? Evoking Dr. Ashok Ranade’s suggestion of the musical pentad in India, religious music is a different genre of music from art music. Religious music consists of repertoire that is religious in content and it may and very often does use ragas and the tala. But the whole musical effect is towards heightening religious fervour. The repertoire of Carnatic music is predominantly religious; but the intent of a Carnatic concert is not religious — it is aesthetic. A good presentation of a composition focuses on correctness of lyrics, of patantara, of delivering raga nuances, of following the kala pramana or measure of time or laya, and indeed of bhava or communication of an emotive content. This emotional content is not religious but musical; intensity of imagination, artistry and delivery must evoke emotion, not literal meanings of words. […]

Even the brilliant Semmangudi Srinivasa Iyer, who was himself deeply religious, clarified that bhakti is essential for a Carnatic music, but this bhakti is for music, not for any personal deity. […]