Consider the following description:
It is a classical music tradition of India, and is devotional in nature. It uses instruments such as veena, violin, mridangam and flute. Its compositions include kriti, varnam, padam and keertanam, with kriti being the most important melodic form. Renowned composers like Muthuswami Dikshitar and Shyama Shastri are associated with it.
Which of the following does the above description best refer to?