They (the inhabitants of Vrajabhumi) would compose all the stories in poetry or have this done by professional poets, and then they would sing about these incidents - of Krsna's killing the asuras

Expressions researched:
"They would compose all the stories in poetry or have this done by professional poets, and then they would sing about these incidents"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

It was the practice of the inhabitants of Vrajabhūmi to compose poetry about the incidents that occurred in the forest when Kṛṣṇa performed His different activities of killing the asuras. They would compose all the stories in poetry or have this done by professional poets, and then they would sing about these incidents. Thus it is written here that the boys sang very loudly.

SB 10.11.53, Translation and Purport

Just as the senses are pacified when consciousness and life return, so when Kṛṣṇa was freed from this danger, all the boys, including Balarāma, thought that their life had been restored. They embraced Kṛṣṇa in good consciousness, and then they collected their own calves and returned to Vrajabhūmi, where they declared the incident loudly.

It was the practice of the inhabitants of Vrajabhūmi to compose poetry about the incidents that occurred in the forest when Kṛṣṇa performed His different activities of killing the asuras. They would compose all the stories in poetry or have this done by professional poets, and then they would sing about these incidents. Thus it is written here that the boys sang very loudly.