The Pudukkottai Gazetteer mentions how Thyagaraja made an unlit lamp getting litup by singing Jyotiswaroopini ragam.
The following account of the incident is given at the bottom of the page 870 of A Manual of The Pudikkottai Volume II, Part I (Second and Revised Edition), 1940:
“Tradition speaks of a strange phenomenon that is alleged to have happened during Sri Thyagaraja’s visit to Pudukkottai. The Raja proposed a strange test assembled in the court. He placed an unlit lamp amidst them and challenged them to light it with their music, without using a match-stick. Encouraged by his Guru who was also present, Thyagaraja sang the raga Jyotisvaroopini. To the wonder of the assembly, the wick it is said, caught fire and shone with varying brilliance according to the gradations of the raga.”